SCHOOL-LIVE! and Dead Rising
Having to venture out to find supplies to live and using whatever you can find as a weapon to kill the zombies, all while being cute anime girls.
Monogatari Series and Beyond: Two Souls
The Monogatari series is so crazy and to put that into an interactive movie type scenario full of qte's and give you options to romance different characters and deciding at the end who you want to be with.
Future Diary and Heavy Rain
Again with the interactive movie type game, but with Heavy Rain style. Going around investigating the other Diary Holders trying to learn their identities and survive. Throughout the game you would switch between characters like Yuki, Yuno, Minene and etc, having all of their stories intertwining. (for people that haven't watched the show the Yuno being from an AU reveal would be amazing) and you'd get choices like at the end with "Let Yuno kill you and restart" or "Become god".
(((there are honestly so many anime that would be amazing in a Heavy Rain game like Death Note and ANOTHER)))
Desert Punk and a GTA/Skyrim vibe
You could play as just another person trying to make their way in life, deciding who to join up with and whether you want to help or hurt people. Maybe you'll just do anything for money in this post apocalyptic world.
Fullmetal Alchemist and Skyrim and/or Fable
Traveling the lands as an up and coming alchemist. You meet people along the way that help you train and you can study alchemy books to learn new techniques. As you go, you take on jobs ranging from repair work to police work. You can decide to be neutral rogue, be a State Alchemist, or aid the Homunculi (maybe even becoming one yourself like at the end of Fable when you become Jack of Blades and are super badass).
Is it Wrong to Try to Pick Up Girls in a Dungeon and Star Ocean: A New Hope
It wouldn't be at the same scale as traveling through galaxies and would be more dungeon crawly like at the end of SO:ANH, but you could run around the town/towns, visiting friends and taking on jobs to find things and such. Build up relations with the girl(s) you like and have cute cutscenes of their interactions. Then you go into the dungeons, wreaking havoc on enemies and going up against tough bosses. (unlike Star Ocean, this could implement online co-op so you could have a party to do raids with). As you defeat enemies you'd be gaining levels so your God could level you up and teach you about your new abilities (I don't know if it would be better to play as a new character and pick your own type and find a god yourself, or if Bell is just too cute with his partners and Hestia. It could go either way but I think I'd prefer playing a set story rather than making your own).
Okay wow sorry, I'm going way too long with this. You just merged my two life passions with this question and I got a little excited with all these thoughts.
Charlotte and a mix between Infamous and Gravity Rush
I already miss Hannibal