Well, I played with many kinds of dicks, one were bigger, the other longer. I would love to have a nice, thick cock up my tight ass, and slimer, longer, to suck. But if I must choose only one, then I will take the longer, for deeper penetration.

Assuming that by taking one, the other remains an 'average' size, I'd definitely take a thicker juicier cock. That feeling of stretching/being stretched is amazing.