Pokemon x Persona with press-turn battle system, pokemons instead of personas and social link mechanics will Ash date Misty, May, Dawn or Iris?

Tales of the Mario. Mario RPG with Tales of battle system and skits. Characters: Mario, Luigi, Peach, Bowser the obvious traitor, Captain Toad, Donkey Kong and Rosalina as DLC (because Bamco gonna Bamco). Daisy gets the shaft again

Halo Metroid would be played to death :).

Skyrim x TLOZ. Link covered in mud slogging his way through a rainy forest on his way to a new dungeon? Day 1.
Also I want Zone of the Enders x Xenoblade Chronicles X.

A Smash Bros game with most/all gaming mascots (Steve, Master Chief, Shovel Knight, Crash Bandicoot, Pitfall Harry, Sackboy...)

I've said this for years, but:

Soul Calibur vs. Samurai Shodown.

Make it NOT lame like the last two SC games, and it'd be bad ass. Then again, make it in the 2D style of SS, and it would also be bad ass. Either way. But it needs to happen.

Phoenix Wright and Professor Layton.

Oh wait, that happened. :P

Yeah, pretty much this for me. I'd wanna see Ninten's finest vs. some of Sony's best characters, with the smash bros style though : P

Also, great to see you're doing a thread Platina : D

Shin Megami Tensei X Fire Em... oh wait!