These are sites with decent looking templates.
Free CSS. A lot of different designers here, but lots of familiar templates, because they seem to give out HTML versions of CMS templates. They are probably screen scraping them. Because this is scraping of GPL code, I think it’s considered legal. To best use this site, search for the author’s name on the web. You’ll find the original author’s website.
Open Web Design. The site is not nice, but the templates are decent.
W3 Layouts. Another directory that isn’t too nice, but has nice themes.
Big commercial site Template Monster has free templates.
Unfortunately, there are a lot of sites with not-very-good templates, or templates that look like they’re old.