Like above I would recommend the following:
Get a steam account (it's free) and pick up:
Knights of the Old Republic - it's available on steam -- good way to get excited for SW:TOR
Guild Wars - same as above. Help get more excited for Guild Wars 2.
Just Cause 2 - I'm playing this casually and every time I go on it's just a lot of fun
The Witcher 2 - I'm also playing this casually. I have more fun with Just Cause 2 but it may be due to not getting too far into this game yet
League of Legends - Fun if you want to just play a game for about an hour. This game is fun, but I recommend finding some good players that won't just quit if they aren't winning.
In addition to those I recommend checking out (also available on steam)
- Bastion
- Terraria
- Dues Ex
- Fall Out (pretty much all of them are fun)
- Borderlands
- Diablo 2 - if you plan on playing D3. Could be fun. I played it recently for awhile and had a ton of fun playing.
The last thign I would recommend is maybe trying an alt. I recently switched to my priest and I've been having a lot of fun (minus having to do the stupid molten front dailies...again...).