Both Carbon and Bovada are as safe as you can get being a US player. Carbon may have a decent MTT lineup, but frankly the ridiculously long late regs with re-entrys on every single tournament just kills it for me. They have a good selection of SNGs which is what I've been primarily playing.

I like Bovada's tournaments better, but I just can't catch a break there. Something stupid always happens before I make it to the money.