I wish they scraped that probley microsoft again I hate them and for you I would recommend half life 2 definatly a good shooter and your system specs can play it
The multiplayer version I had a brief look at for HL2 was running around and between two buildings with an enormous parking lot inbetween. There you were basically running around in circles. Sometimes you came back to life behind one of them and had to travel the distance to get back into the action. That was only one map there however. There are various maps for each game seen on the numbers of different servers.