In addition to the CFS videostore, my two favorite and most reliable sources for DVDs are:
http://www.tlavideo.com and
http://www.amvc.com
TLA video carries mainstream gay DVDs, soft-core gay DVDs and hard-core gay DVDs. I never waste money on the soft-core stuff and some of the mainstream movies are good even though they rarely have any sex shots. The hard-core DVDs show explicit fucking and sucking. Although they carry some "amateur" DVDs, most of their stock are from "professional" companies and have full color printed cases and discs.
AMVC sells "amateur" videos that are not as slick as the "pro" videos, but some of them have a certain charm because they are as close to viewing real sex as you can get. You can tell they were shot by one guy and his friends like the CFS DVDs are shot. Each producer has his own favorite look in guys (just as CFS does) and you can often find neat stuff.
http://www.vidkidtimo.com has always had good stuff, but the owner/producer has gone on sabbatical for awhile -- you can look at his for sale pages, but you can't buy any of them until he puts the buy buttons back on the web pages.