I know, I know, everyone's excited about D3, the Black Market AH in Mists, and the panda dances. Well, the servers don't come up for 7 hours, and I have Renn Faire flu anyway, so I'm going to talk about something else.
My Top 10 Most Played Games (in terms of enjoyability multiplied by /played)
1) World of Warcraft. Need I say more?
2) Lord of the Rings Online (still playing and enjoying)
3) Elder Scrolls: Oblivion (I played to heck and back, modded the crap out of it, then played it some more)
4)Baldur's Gate 2 (the old Black Isle PC game. God, I loved loved loved this game)
5) Neverwinter Nights (and all the expansions and the expandability of this game is near mind-blowing)
7) Icewind Dale
8) Icewind Dale 2
9) Fallout 3
10) Diablo 2
Now, notice that most of the games up there can be moded or altered/expanded? That's part of why I love/loved them so much and kept coming back to them. So, I figured I'd give you a list of mods I'd want if I were replaying them (from what I can remember)
Oblivion: the easiest, since I'm reinstalling it now, and finding the mods I loved. All mods can be found at http://oblivion.nexusmods.com, and signing up for an account there is probably a good idea if you want to play with modded Oblivion, Fallout 3, or Skyrim, since the same account works for all sites on the nexusnetwork. Also, I used as a starting point this post from TwentySidedTale to remind me of stuff.
1)the unofficial patch (also get the Shivering Isles and Unofficial Official Mods patch if you have those)
2)BT mod (cause the original interface annoys me)
3)Oblivion Mod Manager
Anything beyond this is optional, but you might want to look at Oscuro's Oblivion Overhaul. Many people weren't thrilled with Oblivion's autoleveling enemies, and this changes that. Also, mods to add more character optimization options and make stuff prettier is always nice. And last, but not least, FCOM is also one I remember playing with. Right now, I'm going to start with the 3 I listed, and see if I want to add more later.
Baldur's Gate 2: Okay, to be completely honest, I haven't played this in a long time (mostly because my discs are damaged). But here's what I remember modding...
I added classes, more character portraits, gave myself the option to skip the first dungeon, and added companions. All the mods I had came from Sorcerer's net, which still exists (wow, considering I remember downloading stuff on dialup from them over the summer while I was in college, that's a long-lived site)
Neverwinter Nights: okay, I added classes, races, feats, and new campaigns. I don't remember specific ones now, and sadly my installation and saved games went poof when my old laptop failed.
BG1 and the two Icewind Dales: not as much modding. Mostly I remember adding a class or two, and using cheat codes to create a swarm of rabid chickens. Sorcerer's Net would again be my source.
Fallout 3: GreenWorld. Makes the wasteland so much prettier. Also, I got more radio stations. I think if I'd gotten more into this game, I would have modded much, much more.
Diablo 2: I didn't even know there were mods for D2 till very recently. So, never modded it.
I tend to start with a vanilla playing experience, then try mods. It's best to keep in mind that mods can really screw with your game, and their hosted sites can go the way of the dodo, so back stuff up! Anyway, hopefully this gives you a few games to look into if you're not into D3, are bored with WoW, or just want to try a new game. These games are all quite old so you should be able to pick them up cheap (try gog.com)