I tried primedice and found the site to be very nicely done, but slow and unreliable. Might have been during a DDoS attack, which seems to be happening to all the dice sites constantly.

Right now I'm with Just-Dice but I fear for the site because someone appears to be consistently winning and have drained the bankroll for an amount in excess of 6000 BTC over a few days. Very nice interface, more reliable than primedice.

coinroll.it is what I want to try next -- very nice interface as well, and they offer API gaming which is what I need. Only downside is the relatively high minimum bid (x1000 compared to most of the other dice sites).

letsdice I just discovered, and it looks very nice and seems to have a very healthy bankroll. House edge is higher than 1% though, although most of that is going into a jackpot so it evens out the odds long term I guess.

- Michael