I'm personally a big fan of roulette and slots and I look for casinos that allow me to use relatively small bet sizes (around 0.001 BTC).
If there's a progressive jackpot, that's also a big plus for me, especially if they don't require huge bets to be able to win it.
So let me hear what you are looking for in online Bitcoin casino's...
Never thought about the progressive jackpot. When I play on casinos I just "focus" on the game I'm playing and I always think that the jackpots are not for me lol, so I never played for them. I usually go for roulette and slot machines that have free spins bonus.
I also like to be able to use small bet sizes, because I don't have to much money to spend so I like to go easy.