I'd go for the Zelda series, and the old 2D mario games (which I love playing on my Wii
)
Favorite shooter of all times has to be Perfect Dark for N64.
I loved Oblivion with it's huge open-ended world and gameplay.
I liked Dark Messiah's swordfighting system.
Loved Penumbra of course! ^^
GTA San Andreas, just because I love driving around like a nut.
Darwinia, which is my fave indie game apart from Penumbra.
Also, Defcon.
Max Payne 2 and the hitman series.
N (best flash game ever made imho)
Prince of Persia series.
Unreal Tournament 2004 (brilliant fast-paced action)
And then for my collection of survival horror games:
Resident Evil series (RE1, RE2, RE3, RE:CVX, REmake for GC, Zero, 4)
Silent Hill series (SH1, SH2, SH3, SH4)
And last but not least, GTA3, just because I edited some scripts to make it more fun
Watch this vid and you'll know what I mean
http://www.youtube.com/watch?v=13A7mRBM5t4