Mainly I'd be looking for graphics mods that add something new to my game, rather than just update the textures.
Unique Landscapes, then. Maybe
Better Cities. Hm...
Alive Waters? I'm struggling to think of purely
graphical mods that add rather than replace. Even those I've mentioned so far don't
quite qualify. But I'll see what else comes to mind. edit: Oh, of course, there's
Elsweyr! how could I forget? And maybe you'd like some of the other new/"new" lands?
Ah, perhaps you'd like some mods from http://oblivionsrealestate.com/?
And if you play a female character, there are lots and lots of clothing mods, if they take your fancy...? Some are available for guys as well though.
I don't really understand the question; what is an example of a graphics mod that some people would like that others would not?
It is *all* a matter of taste, just like playstyle mods, or music, art, food, whatever.
For example, when it comes to retexturing, some people must have QTP3, whereas others don't care for it at all. And so on...
I have a GTX 460 with 1 GB onboard memory, a Core 2 Duo at 2.13 GHz, 3 GB of RAM. I'll probably be limited by my processor, right?
Specs seem fine, to me. And since you don't want replacers, I imagine you won't have much difficulty, depending on whether you thrash things like scripts/AI.