Yes, yes, Arjun Arora's theme names are getting a little pretentious(!), but the themes themselves are pretty nice, with the two premium titles Black Pro Belle Transparent & Galaxy Extreme Reloaded HD screenshotted below. Worth a quid or so if you like their look, both optimised for AMOLED screens, with deep blacks and (in the latter's case) rich purples.
Here's Black Pro Belle Transparent in action:
And here's Galaxy Extreme Reloaded HD installed on my Nokia 808:
In either case, there's good third party icon support and some thought gone into the way the various theme elements interact. You can grab the themes for a pound or so in the Nokia Store: Black Pro Belle Transparent and Galaxy Extreme Reloaded HD.