As a PC gamer with a damn nice computer, I have to say one of my favorite things to do is Mod games to no end trying to tailor them into exactly what I want and push there graphics as much as possible. One of my favorite games to do it with is Oblivion as there is such a huge modding community for the games, it's so easy to mod, and ther are so many tools to do it with.

So what mods if any do you guys use for Oblivion?

I have more then 150 mods on oblivion right now so I'm only going to list a couple of biggies that I think apply.

Obscuro's Oblivion Overhaul -  This mod adds so much to the game that it would take about 10 pages of this thread to explain it all but some of the biggies are the fact that it adds over 300 different mosnter types and not cheap reskins, adds tons of armor and weapons, and a huge biggie for me is changing the "creatures level with you" factor and instead has creatures strong as hell and set levels on things. Overally this will make the game much much harder

EXP leveling: This for me is an absolute must that NEEDS to be combined with Obscuro's. The two together are like bliss, and makes the game feel much more like a traditional RPG leveling system and work very very well together since everything is leveled appropriatly.

Qarls Texture Pack: If your computer can handle it this texture pack is a MUST have. It puts many games even today to shame. It retextures "almost" the entire game. I have a ton of knick nak retextures to go along with this for the things it doesn't cover.

"OC Darker Night" and "Real Lights":  I put these two together because oblivions fake lighting is pretty horrible. With these combined i have never seen better lighting for a game during the night.

Music: Not really a mod as you can actually add whatever music you want with oblivion without any special file other then your own mp3's. I have a really nice combination of Silent Hill, Final Fantasy, and Demons Soul music that accompany the game perfectly without losing the feel of Tamriel.

almost makes me want to finally get Oblivion lol, but I have more than enough games as it is.

MMM(Martigen's Monster Mod) and Mida's Magic are also two other good ones. 

you just got me interested in playing oblivion again :P

Like everybody else is saying, I've been thinking of reinstalling Oblivion.

It's been a very long time since I last played it, but I remember a few mods like a texture pack, improved weather and skies, LOD texture replacement and having a vendor in one of the cities sell things like the vampire cure potion.

I'd certainly like to check out the other mods that totally overhaul the game because I became really bored with the combat (and monsters that level up with you) and leveling up that after I beat the game and went back with a new character, I'd just noclip and use the console kill character command because I was so bored.

I go with FranMMMOOO. And a bunch of others. I'm excited that Oscuro's working on New Vegas!