I'm not a big fan of the MDMA/coke combo. You get a good MDMA high going, and then the coke tends to cancels it out (for me at least). Also, if the MDMA is speedy, things can get sketchy. MDMA + Ketamine is a great combo. Coke + GHB is also a good one, the GHB cuts through the coke sketch waaay faster than liquor. Just don't overdo it if you don't have much G experience. G flailers are funny.