Hmm, at the time I recall being floored by Qarls Texture Pack(both for it's transformation of various textures and the hell it inflicted on my GFX card). Your graphics card still might struggle a little depending on resolution. IIRC the stock clocks are pretty low on the GT 240(550mhz core/1360mhz shader/3400mhz memory), perhaps you will have some OC headroom if necessary?

http://planetelderscrolls.gamespy.co…Detail&id=2363

Other than that one I don't really recall much… You could always look through the top 100 files on TESnexus.

A few off the top look at least a little interesting:

Midas magic spells of Aurum
Natural Environments
Elsweyr the Deserts of Anequina
The Lost Spires