Norm de Plume

CDUniverse isn't mentioned much around here, but I think it's one of the best DVD merchants.
Prices are always among the lowest (competing with DDD and Pacific), shipping costs are very reasonable (though not free or flat-rate like DDD), but best of all is the inventory. If CDU does not have it, chances are good it's not available. It is always the first DVD website I visit when searching for rare titles.

Funk

I've never used them for DVDs, but I've bought CDs from them and their service is all-around great.

Calmuser

with their highly rip-off shipping rates for shipping internationlly, I don't think I will ever try them.

JAA

I've never had a bad experience out of 10 (or so) orders. They also have a great selection, but I'm not that thrilled with their prices.

Quatermass

I'll second that emotion. Too many painful memories from the old days.

Norm de Plume

I don't know what you're talking about. To Canada, standard is $4.99 + $.85/ That's very reasonable, minimally at-cost. If you want to see ripoff rates, look at the $8 + $2/ charged by DVDPlanet and DVDEmpire (don't know if anyone even bothers with these two anymore).
Prices could be even better, but they are always among the lowest and sometimes the lowest for certain titles. Also, they carry some DVDs no one else has.
I too had a bad customer-service experience somewhere around '99, but since then it has been smooth sailing. I use DDD most often, with Universe as a strong second.

wanderlust

yeah, the year 2000 experience almost stopped me from getting my dvds via the internet. my problem of not getting my stuff was never settled.