Building a new PC, what games to get?

So my dad and I are building a new, state-of-the-art (for now) PC for me to use, and I was wondering, CAG, what PC games are really good? I'm open to any genre, but I've never had a computer that could handle gaming, so I'm kind of in the dark. Thanks all!

FPS

• -Crysis series (Mostly eye candy for your new machine)
• -Anything from Valve. Half-Life series, TF2, Portal series, Left 4 Dead.
• -Battlefield 3. Not released yet, but may be the best looking game out there to test your system.

RPG

• -Elder Scrolls 4: Oblivion & the upcoming Elder Scrolls 5: Skyrim
• -The newer Fallout series
• -Torchlight, if you were a Diablo fan.
• -Dragon Age: Origins
• -Mass Effect series

RTS

• -Starcraft 2, if you're in to that sort of thing
• -World in Conflict
• -Company of Heroes

Watch for sales on Steam at http://store.steampowered.com/. It's the best place for digital distribution, and they regularly run amazing deals.

Check out my list. In my sig and in the sticky.

What genre of games do you enjoy?

Civilization 4 or 5..either one
Borderlands
Just Cause 2..just for the mods alone
S.T.A.L.K.E.R. series
Warhammer Dawn of War series
Mount & Blade Warband/With Fire and Sword

*edit* Honestly just wait till the Steam Black Friday sale and budget $50-$100 (or more if you want) and you will have plenty of games to play. lol