This forum is a graveyard, yikes!
Hopefully my post will help get some talk happening.
I'm going to be talking about a several things. Enjoy!
*forgive me purists but I'm using dub names 
1. The English voices in the series
*I won't cover every character
Despite the edits to content and at time cringe-worthy lines from re-writes, I really love most of the English voices.
R. Bruce Elliott is one of my favorite voice actors at Funimation and even though Case Closed was one of his first anime roles ever, it still holds up well after all this time IMO. He was PERFECT as Richard! Definitely my favorite voice in the entire dub!
Colleen Clinkenbeard as Rachel. It was one of her first lead roles I think, (the other being Eclair in Kiddy Grade when she first started at Funimation) and although Rachel was never the most interesting character, Colleen was also well cast for this role.
Alison Viktorin as Conan. Had a great "know-it-all" kid voice. Had great chemistry with all the others.
Jerry Jewell as Jimmy. What a great role!. Still one of my favorite roles of his and I'm sure he loved that he didn't have to challenge mouth flaps the majority of the time.
Mark Stoddard as Meguire. Every time Meguire and Richard shared a scene it was brilliant. As I'm sure many of you know for dubbing every actor records separately. I thought the interaction between these two was great and Meguire is one of my favorite Mark Stoddard roles. Accent probably wasn't needed but it sure made the character more interesting to listen to for me.
Bill Flynn as Agasa. I'll admit the accent wasn't necessary but I thought it did bring some charm to the character and was still a good performance.
Dameon Clarke! Off topic but I was thrilled that he returned for Dragon Ball Z Kai. His voice for Cell in DBZ is one of my favorite dub performances of all-time (IMO one of the better VAs when Funimation first started out) and he's even better in Kai!
Back to Case Closed though I think this show was another good example of his range. I'm sure some viewers thought George's mush-mouth type voice annoying but I think it suited the character's personality.
After moving the L.A. Mike McFarland took over the role. I liked McFarland's voice too but I felt Dameon's take was more unique and entertaining.
I also enjoyed hearing Dameon as Inspector Worthington. I thought his timing and delivery for some of the lines was fantastic.
*asks questions* *threatens the suspect*
"Where were you at the time of the murder?!"
"Hey don't stop now, you're on a roll.... DID YOU KILL YOUR FATHER?!"
Cynthia Cranz is usually cast as mothers in several anime who only appear in a few episodes (the Dragon Ball franchise being an exception of course) but Mitch was the first time I heard her voice a young boy. Nice change for her and it was a good supporting/recurring role for her.
Monica Rial's voice for Amy IMO was very cute, sweet and a great fit.
Julie Mayfield as Eva Kaden. Shame she's not involved with more anime, I think she brings a unique presence to many of the characters she voices and Eva is a good example.
Laurie Steele as Vivian Kudo. Chris Sabat mentioned on the commentary for One Piece (episode 1) that Laurie Steele is usually cast in roles where the woman is overweight, harsh and "manly". He laughed because Laurie Steele is obviously nothing like that in real life but when they need someone to voice that kind of character they get Laurie Steele.
I really liked her voice for Vivian because it sounds so different from her other roles. Younger and dare I say a bit sexy at times? 
Laura Bailey as Serena Sebastian. Character came off as a spoiled annoying bratty rich girl. Laura nailed the part!
Kevin M. Connolly as Harley Hartwell. Had a believable voice for a teenager and an actor I'd like to hear more of. Funimation seems to be lacking male talent to play teenagers or the voice directors just really love casting the same VAs in these roles... *AHEM*
Gwendolyn Lau as Kirsten Thomas. Another underrated voice actress who I thought did solid work. I'd like to hear more of her too.
Kent Williams as Detective Mangum. Usually cast as villains or serious knowledgeable characters but it's great to hear him in some comedic roles too.
Some fun facts:
- Sonny Strait voiced more characters than any other person in the entire series
- Jamie Marchi voiced more characters than any other voice actress
- Chuck Huber voiced more bad guys and jerk type characters than anybody else
2. Order of the 6 movies
My ranking from favorite to least favorite
*The Phantom of Baker Street (Movie 6)
*The Fourteenth Target (Movie 2)
*Countdown to Heaven (Movie 5)
*The Time Bombed Skyscraper (Movie 1)
*The Last Wizard of the Century (Movie 3)
*Captured in her Eyes (Movie 4)
Movie 6 hands down is my favorite. Plot was superb, and the dub ended a on high note. (Unless there are more movies in the future? 
)
Movie 2 I don't know why I like it so much. Maybe it was because it was a rare occasion where there were many supporting characters who all actually got a decent amount of screen time and weren't just there for the sake of being there (all were connected). Plus an amusing explanation for why Richard and Eva separated.
Movie 5 actually had the Black Organization involved!
Movie 1 may have been predictable for some stuff but I felt it had fairly good pacing and was a great first effort.
Movie 3 had the best post credits ending ever!!! I didn't really care for the story itself though.
Movie 4 is my least favorite overall but it had some moments (e.g. flashback of amusement park)
3. Notable Performances in the Movies
Troy Baker as Gin and Chris Sabat as Vodka in Movie 5. Huge improvements from their debut in the series.
Steve Powell as Professor Moriarty in Movie 6. Some of the extras had over the top fake sounding British accents but IMO Steve Powell gave a memorable and solid performance for a fairly small supporting role.
Kate Oxley as Simone in Movie 4. I think she's a very underrated actress (*hint* should be in a lot more anime *nudge*) and I'm glad she was cast in as one of the more prominent female characters in this franchise even if it was just for the one and only time.
Cole Brown as Officer Tome. I love his voice for this character he sounds so jolly! Not a major character but a recurring one. Did you know that this character had several different English VAs in the dub? He wasn't named for the longest time so I guess I can't fault the dub director(s) for not keeping track of his voice actor in a previous episode. Plus so many characters in this show look alike.
4. Biggest WTF moments
- guy kills father so he can write a book about it and become famous? LMAO
- guy almost burns a girl to death while she's passed out so he can rescue her and make her fall in love with him? *facepalm*
- Harley Hartwell from Alberta?
Just no..... 
- some of the truly awful dub names for some of the guest characters (nobody would ever name their child that) LOL
5. Favorite moments
- Movie 3: Phantom Thief Kid poses as Jimmy Kudo in front of Rachel and Conan
- anytime Richard accused someone and pissed off people for being wrong
- Meguire FINALLY noticing that wherever Richard goes there are always dead bodies
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I noticed that some of the voice actors for the dub were completly different from when I originally watched this show a few years ago.
So am I to believe that Funimation Re-Dubbed the show? or did they do like the did with Shana?
Hmm, well only one voice changed, which was Genta/George due to his actor moving, I can't say that anyone else changed. Uh, I guess Vodka did get re-cast (thankfully) with Chris Sabat, but other than that, everyone else is the same.
While I am what you would call a connoisseur of dubs, I will say that Conan is one of FUNi's lowest quality efforts. Don't get me wrong, it's still very good and is in no way 4KIDS bad or anything, but it has the most faults of any of their dubs, including the original Dragon Ball Z dub (not the ocean one, the one that had Chris Sabat playing half the cast
). Most of the cast is really good, like Elliot as Kogoro/Richard, Viktorin as Conan, Clinkenbeard as Ran/Rachel and so on, but there are way more miscasts than any other show they have done.
Heiji's/Harley's voice is so bland and doesn't fit the character at all (not even the supposed Canadian element makes sense as his voice sounds more like a preppy than anything else). I don't know who the actor is, but I've never heard him him in anything else, I almost wonder if he's like the guy that get's Mike McFarland his coffee and they just had him record for a character they thought was only in one episode (at the very least I do think that they assumed he was a throw away character since he only appears once in the first 50 episodes they bought). Takagi/Wilder (that was the best localization they could do?) is equally bland and unpleasant. You can tell they just thought he was a background character and cast him as such, not that I can blame them as up until season 6 (by US counting) he basically is. Kobayashi (I don't recall her English name, the kid's teacher) is another miss. While I love Stephine Young to death in One Piece and think she is a fine actress, her voice doesn't fit the character. They should have just let Cranz be double billed and have her do it. Kobayashi is basically the "mom" of the group and no one fills the role better than Cynthia Cranz
At first, I hated Troy Baker as Gin because he sounds awful in the first episode, but then I saw "Countdown to Heaven" (my personal favorite of the 6 movies I've seen) and his performance was so much better in that, it actually completely changed my opinion of him in the role. I wish he sounded that good in the episodes, but maybe it's more about directing in this instance. It seems like one of the major issues with this dub (aside from the name changes/Amercanizing, which I heard was TMS's doing and not FUNi's) is a tendency to cartoon up many of the voices. Gin and Vodka both sound like generic gangsters in the first episode and Agasa has that silly Albert Einstein accent. Every so often you will get a random character with similar problems. I realize that Conan is like 600 episodes long, and actors will need to be reused and such, but doing bad impressions of gangsters and what-have-you isn't the way to solve that problem. One Piece has almost as many episodes and maybe even more characters and yet it's dub doesn't need to resort to such things (which is funny since OP is much more comedic than Conan).
Conan's mom, oh my god, that voice is straight up awkward. No offense to the actress, she gives an okay performance, but her voice is extremely out of place. All I can say is that she doesn't sound like an ex-starlet (unless said starlet took up chain smoking when she retired).
I know it sounds like I hate the dub, but I don't, it's just not up to the standard set by dubs like Fruits Basket or FMA. It's a shame because FUNi is almost the defining example of quality English dubs and with the localizing removed and few casting tweaks here and there it would be perfect. Oh well, it's still better than Buso Renkin's casting