If funi did acquire the rights to a lot of old pioneer/adv films, there would be a lot that I'd like to see.
But from funi's current titles, here are a few I'd like to see:
Dance in the Vampire Bund
Aria the Scarlet Ammo
Cat Planet Cuties
Comic Party Revolution
Daytime Drinking movie
Gunslinger Girl series - I think this one is on the channel already, not sure
Heaven's lost property
Is this a Zombie?
My Bride is a Mermaid
Nerima Daikon Brothers
Rosario + Vampire
Save Me Lollipop
Tenchi series in order - excellent series btw!
The familiar of Zero
The Sacred Blacksmith - not sure if this is on the channel or not
Trigun - a must to see in honor of badlands rumble coming out
Other non-funimation titles that I'd like to see,
High School of the Dead
Nana - I want to say it was on the channel at one time
The Melancholy of Haruhi Suzumiya
I love the channel. I use it as a way to sample anime. If I like it, I'm out buying it. If I don't, then it's not that much lost.