Huh. I've answered two of these threads in as many minutes...oh well.
Here's my response from the last thread.
A popular website that I can think of off the top of my head is ThemeForest. I wouldn't recommend looking at these sites for help because many use large images and too many fancy design-only plug-ins that slow down the page and make it a boggy mess.
I would also recommend Patrick McNeil's Web Designer's Idea Book which is an absolutely fantastic book full of inspiring and beautiful web designs organized by theme. Each of his two books contains probably 400 (at least) of the best websites out there. Buy it on Amazon (it's really cheap atm) or get it from your local library (they should have it).