Actually, I've found that the best, cleanest, sleekest and most professionally created theme (for me) thus far is this combonation:
-Illumine Theme
-Illumine Weather Icon
-3D Fiction II Movie Wallpaper
I would post screenies but I'm typing from the iPhone and don't know how.
It's just very....... pretty! Not in a girly way or anything, the icons are just fantastic.
It doesn't have any special splash screens or anything, just icons, battery theme, and weather icon, but it's very much a perfect replacement for the 'official' theme for the iPhone.