This site usually has some stellar prices on a lot of random things. Shipping is pretty fast, and so far, I have no complaints. braindamagefilms.com is also pretty cool, and I have found some really funny t-shirts on there.
Nice selection of dvd's and some cheap prices with free P&P, delivery times to the U. S is about a week or so, which is fast from the UK, i recommend for your hard to find indie dvd's.