I'm sure this has been said already but... none.
There are a lot great properties from the old days, and those games were certainly good, but current-gen gaming is stagnant enough with constant sequels and remakes and revivals of old properties. What we REALLY need is more interesting original material.
But, if we're going to be remaking stuff anyway, we should get some Mechwarrior action going on. If they remade the Titanium Trilogy, I might be okay with that. Hell, remake Earthsiege, or even fucking G-NOME for God's sake. Anything to get some current-gen mech sims on the market.
Seriously, when did we lose interest in stomping around in giant robots? But back to my original point, I'm really looking forward to that indie mech game--what's it called--Steel Hearts or something?
EDIT: I forgot Heavy Gear. Heavy Gear 2 was one of the best mech games to ever come out on the PC.
Also, that reminds me, Armored Core should have been a PC game series. That game utilizes literally every single button on the Dual Shock, and it's cumbersome as all Hell. Mouse and Keyboard control would have worked about 100x better.