Depends on what matters to you. If you like good story with pretty decent graphics and some very unique guns, go with half life 2. Then, after you finish that, hit up half life 2: episode 1 and half life 2: episode 2, and get ready for the next half life game that is said to be coming out soon. If you're looking for some interactivity with other players, then it's time to check out World of Warcraft. Just be careful, though, it's reeeeally addicting. Do you have any additional info on what kinds of things are important to you?