Here are mine!

1. Majin Tantei Nougami Neuro - I can't even properly explain to you how fantastic this manga is. If you've never read it, do so now. The art in the beginning may turn you off, but it gets better and the read is completely worth it. Matsui Yusei is a genious- he definitely thinks things through and allows for everything to connect together. Don't believe me? Just read for yourself.
2. Sakamichi no Apollon - I'm pretty sure I shed some tears for this manga. It's not perfect, but it manages to tug at your heartstrings and really make you feel for the characters. I have a definite soft spot for jazz, so there's that as well. I don't think I've ever felt as strongly towards fictional characters' romantic relationships as I have with this series.
3. not simple - An all-out tear-jerker. And you thought your life was bad? Be aware- you will come out of this manga utterly depressed. There's nothing really happy about it. The art is simple yet effective (how I love Natsume Ono) and definitely unique.
4. Kuragehime - I'll be honest, I'm very behind on the manga, but I did watch the anime a while back. I love all of the characters dearly, especially the protagonist, Tsukimi. A really funny and relatable story.
5. Yotsuba&! - Who doesn't love a good dose of Yotsuba in their life? You can never go wrong with the lovable clover-haired tyke! Sweet, comedic, and lots of fun.
6. Watashitachi no Shiawase na Jikan - Yet another heartbreaking one-shot (sorry!). I read it a long time ago so some of the details are a little fuzzy, but I definitely remember it being very well done.
7. Genkaku Picasso - This series was an unexpected surprise for me! I borrowed the first volume from a friend on a whim and became instantly hooked! The art is surreal as is the story, but that's what I love about it.
8. Seven Days - Normally, most BL stories I find are lame and predictable, and this one sort of is predictable itself, but it's just... it's different from most I've read! It's heartfelt and really cute.
9. JoJo's Bizarre Adventure series - I've only just barely scratched the surface of this series and I'm in love. I went into it to make fun of it and ended up unironically enjoying the hell out of it. I'm somewhere in Part 2, so I've got a long way to go. But I can tell it's gonna be great.
10. Assassination Classroom - I put this manga at the bottom of my list simply because it only started publishing this summer, so it still has a long way to go before I know for sure what I think of it. But for now, I adore it. It's by the same mangaka that did MTNN and it's just as hilarious, bizarre, and unique. This title is a little more audience-friendly as opposed to MTNN in terms of art.

Lets see it's easier for me to say my top 12 manga which are

1. Rosario Vampire
2. Hunter x Hunter
3. One Piece
4. Haganai
5. Attack on Titan
6. Toriko
7. Golden Boy
8. Freezing
9. D.Gray-Man
10. Hungry Joker
11. Kuroko's Basketball
12. Seikon no Qwaser