Should I buy my wetsuit that fits tighter or looser?

You don't wanna wear anything under your suit, go with the smaller size, if it's tighter you're warmer and drier when you get out, I finally grew into a mistake wetsuit that I bought, I bought it about a size too big and have been freezin my *** off in it, finally grew into it, it's real tight and I suggest you get the tight one... soooo much warmer