Please help with advice on 1v1 Multiplayer Games

[Vitrolic]

Hi there,

Some friends of mine have just got 2 PC's, one dual core with 9800GT and one pentium 4 with 9600GT to give basic specs.

They want to network the PC's and play games, just wondering if anyone has any reccomendations on decent Single Player and Multi-player games out at the moment. Also Multiplayer does anyone know of any games which are still fun 1v1.

This is what I have come up with so far

Single Player -
Mirrors Edge
New Crysis
Far Cry 2
The Witcher
Devil May Cry 4

Multi-player
CoD4
CoD5
CS : Source (I know )
Baboviolent
left4dead
Q3 Arena
Warcraft 3

If anyone has any other suggestions, please post

 

[Pe-Killer]

Multi-player a few cool co-op games me and my friends play.
Gears of war
rainbow six 1 and 2
Gta 4
Ghost recon

 

[HideInLight]

Unreal Tournament 3

 

[PostmanPot]

Starcraft...