I know play.com. They are pretty cheap but the only time I ordered something there it took 23 days for the item to arrive. I know that it's not Play.com's fault and maybe I'll have more luck next time but it was still 13 days more than I expected.
I had the same problem with deepdiscount.com. Ordered games in november from them, and by christmas, they still hadn't shipped them. They wouldn't cancel the order either since they said they aren't able to do that. Needless to say, I vowed never to use them again.
However, the challenge is that these experiences aren't always this way since it all comes down to what they have in stock. Still, it's enough to leave a bad taste in your mouth.
And 5 dollars for bioshock annoys me when i got it for 15 only two weeks ago lol.