Demons souls (or is it demons soul, demon souls?) Japanese RPG for the ps3, it is in English though (apart from some audio but has subs in english also, the Japs think English is cool etc...) You can join parties of upto 4 people I think, lots of dungeons to conquer and dragon, golum, demon bosses etc to slay. Guess you gonna need three mates with a ps3 and a copy though... Would be a pain in the ass to lan it up and have four tv's in the same room lol. Also white knight chronicles is comeing out this year that also looks good.
Elder Scrolls 3 Morrowind, the predecesor of Oblivion is also excellent. Graphics aren't as great but mods still make it beautiful. Much bigger world than Oblivion and there are many, many islands and caves you can go through. Not as less "centralized" and more of an "Outlandish" feeling which is great. Monsters aren't levelled so you'll see uber pwn baddies or weak little rats.