Absolute cross
Original interfaces, Photoshop and PSP tutorials, graphic resources...

GuiStuff
A site that offers high quality interfaces, DHTML and Flash wizards for creating menus and navbar, an active and interesting forum. A reference !

Ann-S-Thesia
A great number of beautiful interfaces, a lot of graphic resources in a rich site, by a talentuous artist.

Steve's website templates
Some home made interfaces and a big reserve of intersting links especialy to web sites containing free templates.