I'm back in the PC gaming business! Games suggestions needed!

[Scoobes]

Errr... let's see. 8 yrs... well, some of these are gonna be multiplat, and I'll mention some older titles you may have overlooked:

I've *'d FPS' which you may want to try before you buy.

The Witcher
Crysis*
Orange Box* (Portal is definately worth buying alone if you don't like the rest)
Age of Empires III (Complete edition now available I believe)
Rise of Nations
Any "Total War" game
Left 4 Dead*
Counterstrike: Source*
Far Cry* (1)
Neverwinter Nights 2 & expansions (1st one is better if you haven't played it)
Oblivion
Fallout 3
Darwinia
Civilisation IV
Spore
Mass Effect
Day of Defeat: Source*
Risen (just released, PC version meant to be quite good)
Bioshock*
Unreal Tournament 2004 & 3
Dragon Age: Origins (soon to be released)
Mount and Blade
Trine

Older:
Deus Ex & sequel (sequel is nowhere near as good mind)
Planescape Torment
Baldurs Gate 2
Fallout 1&2
Age of Mythology
Age of Empires I & II
Warcraft III + expansion
Rise and Fall: Civilisations at War

Also, most multiplats tend to look better on a half-decent PC so a game like Modern Warfare 2 is usually a good bet on PC. In general, Steam is a good place to browse for hidden gems that you may have missed, and they do lots of good deals. Steam is essential for my PC gaming thesedays.