MeriSkin is the UI that I've been using for a while now. It has a wood texture for the backgrounds with green buttons and edging, for us tree-huggers :-)

I play in 1280x1024 mode, with a viewport of "/viewport 115 0 1165 810". The borders are thin, though, so it's usable in 1024x768 and smaller resolutions (ymmv).

Note: The preview image shows T. King's spell icons (not included in the zip file because, well, they're not mine ). I like those icons far far better than the originals and highly recommend them :-)

Update 2003-11-07: In additon to including the files for the target ring (since EQ won't load them properly from the default directory), I've done some reworking of the options window, especially the colour selection tab. I also took out the pet window because I find it hard to update without playing a pet class (the file was renamed to EQUI_PetInfoWindow-unused.xml).