Man, a straight port of Donkey Kong 64 would be absolutely great. Zero changes: just slap it on a kart, charge me $70 dollars, and I'll absolutely lose my mind over it, apparently.
Unironically, there are quite a few games in established genres that I'd be really hyped for. To name a few of the weirder ones...
...Star Fox reborn as a Mass Effect 1 clone
...Call of Duty or Battlefield: Rome
...ARMS reborn as a Halo 3-style arena shooter
...a new Banjo-Kazooie... in the Style of Nuts & Bolts
To name a few of the less weird...
...a sequel to Thief: Deadly Shadows, or, barring that, a modern clone
...a new Deus Ex
...a new inFamous
...a new Jedi Knight
...a new Kid Icarus... or, yes, even an Uprising port. Sigh...
There are also a few genres and mechanics that I'm always interested in: create-a-class TDM FPSs (none of this BR BS); anything with interesting physics; anything with interesting, fluid character movement; anything with interesting if not necessarily realistic A.I.; anything with multiple systems that interact, allowing the player to make their own fun; and, finally, the dream: an ARPG MMO that focuses on PVE but doesn't have itty-bitty environments and constantly repeating quests (looking at you Destiny).
And then there are all these tweaks/variations on popular themes and genres that I'd love to see tried, but, in an industry that prioritizes safe sequels, "A-to-Awesome" contextual gameplay, cinematic setpieces, and corridor level design, I don't hold out much hope.