Well, although pretty much all of them have slim to no chance of happening, i'll do a top 5 anyway.
Shenmue III
Streets of Rage IV (keep it 2D, perhaps have 4 player co-op instead of 2, more moves, more playable characters, and of course Yuzo Koshiro doing the music)
Onimusha V
Dino Crisis IV
Fighters Megamix II/Jet Set Radio III (either one will do nicely thanks SEGA)