Just finish Oblivion and the expansions recently and fairly new to the modding scene of Oblivion, so I was wondering what are some of the mods that greatly enhance the gameplay like adding new quests, whole towns and maybe a few new dungeons and storyline? I tried to find some mods but the amount of mods out there are too many for me to select.

the doesn't really add stuff such as quests but if you havn't already....Rens Beauty Pack and a face resolution up......increases character model face qauility and beauty pack allows for more character customization.

I had a hell of a lot installed at one point (around 12GB of mods alone). I'm still searching for some, but I can list a few of the better ones.

I have used Quarls Texture Pack since I've been playing. It makes the, otherwise dull world pretty damn amazing in places.

BTMod is a must. It tidies the interface, and makes it much more user friendly. I wouldn't play without it.

Unique Landscapes gives a great sense of realism to the world. There are more ruins and farms etc. I'm not sure if this includes the "Ancient Yews" mod, but that's also worth getting.

But, if I'm honest, I couldn't create a better list than this. I have used it a lot myself. The above are just some very nice basic realism mods.