For my own podcasts (found in mixcloud), I do cratedigging in soundcloud (mostly). It sure is time-consuming, and there are loads of complete shite in there, there are also the gems to be found. The UI of soundcloud is also quite good. It can also be free, since there are a lot of tracks available as free downloads.
Ragejunkie.com is another place where I’ve found something, and its all free downloads, but the UI is much less convenient.
On my gigs I play mostly mainstream stuff, though. Weddings/corporate, you see.