Windows 7: Best games to play Pc?

hey guys ive just finished my new pc build for gaming it was my first gaming build so i was quite happy of the results. Jusst wondering im gunna be buying games for this sucker and wanted to ask you guys whats the best games on the market for online experience
thankyou for reading

Updated specs would help. That HP you have listed there now isn't up to much of anything.

no thats my old pc this is my specs of new one

Coolermaster storm
4gb kingston CL5 1066mhz
Asus le V2
Phenom II x4 955
Ati sapphire HD 5770 1GB GDDR5
Artic freezer pro7
OCZ power supply 55OOW

any games from vavle are awesome. even though some are like 4-5 years old millions of people still play them. i highly recommend GMod ( because its awesome) and CS:Source (which gmod needs to run) which willl come to something like £14.99 which in dollars is like. $23 - $25

I'm currently playing BFBC2, NFS Hot Pursuit, Crysis and COD Black Ops. I'm running the same CPU and a slightly better graphics card (GTX470). NFS Hot Pursuit should play EASILY, it hardly taxes my GPU...

Mount and blade Warband - hack slash adventure game (runs on any pc)

Americas Army - Fun combat simulator made by the us army and its free. But has some bugs (runs on mid - high computers fine)

Sins of A Solar Empire - Fun space RTS, has large mod community and looks great. The mp is kinda dead though (runs on any pc)

Urbanterror - Amazing free opensource shooter, best compared to games like counter-strike but also very different then cs (runs on any pc)

Battlefield 2(not bad company) - Perfect mix of tactical and fast paced combat. Maps are big, and vehicles kind of dominate but should not be overlooked.(runs on any pc)

All these are great

Sorted by awesomeness:

- Battlefield Bad Company 2
- Crysis and Crysis Warhead (insanely demanding games so don't even try maxing them out)
- Mass Effect 1 & 2
- Dead Space 1 & 2
- Grand Theft Auto 4
- Killing Floor (better than Left 4 Dead series IMO)
- Red Faction Guerrilla.

I'll put in votes for the 2 mass effect games.
Also an additional suggestion to any source engine / valve games.
left 4 dead, left 4 dead 2, counter strike source, half life 2 + eps 1 and 2, Portal etc... all good games that will run great on that system.

thanks guys i think ima be getting bfbc2 and mw2 and black ops cheers all!

do you really want to get them all, and nothing else?

they are all shooters, don't you want some variety?

in my opinion, bfbc2 is best for long-term online fun at the moment. i'm really enjoying the vietnam expansion.

as for other genres, dirt2 is a great racing game (single or online), and fallout 3 (the original rather than the weaker new vegas) is a shooter/rpg that should keep you amused for a very long time (but not online).

what sort of games do you play apart from shooters?