Everything looks good! Everything will work together, just fine.
And, yes, you will be able to play CSS, HL2, and BF2.
The only thing that really caught my eye was that you dont have a CD burner.
I would consider a CD burner to be a neccesity, not so much for pirating, but for backups. Backups are super important, even if the computer is only for gaming. How upset would you be if all of your saved game data got destroyed from a system failure?
Intel E6750...........PSN: ELBATROP
XFX nForce 650i Ultra
Patriot PC2-6400 8GB (4x2GB)
36GB WD Raptor
Samsung SyncMaster 931c
Samsung SyncMaster 750s
Windows 7 Home Premium 64