Taking a shot at Demigod right now, and its preeetty interresting, always liked DotA but never had the commitment to stick around getting my ass handed by pros..
If you're the social type with money to spend, Guitar Hero World Tour with the full band pack and 3 mates is great fun if you are into that kinda stuff.
Orange Box, must have

Still alive! \o/
What else.. Oh assuming you have an Xbox360, dead rising is made of 100% awesome zombie killing in a mall (L4D zombie killing go home and weep).
Again assuming there is an Xbox available (else try and find and DL a pc port of these) Call of Cthulhu: Dark Corners of the Earth (if you know Lovecraft, this is a true top 3 game of must own). Pshyconauts have great humor and a fantastic gameplay even tho a bit short. Else Farenheit is a great storry but maybe a bit too short and gameplay-wise a bit dull (Indigo Project if you are from the USA).
hmm what else.. Warcraft 3 and Starcraft are still some of the best games out there. World in Conflict is great if you play alot of LAN, also Europa Universalis if you like raw strategdy. Else either of the Might and Magic series are great fun (Tho the RPG one will need a windows 2000 or older to run for the older versions of it, number 7 For Blood and Honor is my fav)
Dead Space is a sweet spook/horro game, tho it is not alot compared to Silent Hill 1-3 and Call of Cthulhu.
Else Diablo 2 is still alot alive (with the 3dr game comming up soon it would be worth to get some pratice in if you wanna go down that road).
/end of rant
Now back to Demigod, Oak powar!