This thread seems to have abandoned the criteria of "two or more generations ago," but hey, allows me to wax lyrical. So, on that note:
-Advance Wars
-Command & Conquer
-Darksiders
-Dead Space
-Golden Sun (if only to resolve Dark Dawn's cliffhanger - I was otherwise fine with the two installments existing as a duology, thank you very much)
-Half-Life (again with the cliffhanger)
-Marathon (hey, if Doom gets a remake, can't Marathon get similar love?)
-Metal Arms (okay, never actually played the game, but as Blizz owns the rights, I can still dream, can't I?)
-Perfect Dark
-Spyro the Dragon (I'm not counting Skylanders as Spyro games, but rather games that happen to have Spyro in them)
I'll give some shotouts to Banjo-Kazooie, Medal of Honour, and Conker, but I'm not really clamouring for their return in the same way as the above series. Just something that would be nice to see.