Despite how easy it would be... Dick or Cock.
There are so many more interesting words! Shaft, rod, member, manhood... and if you want to talk dirty... Stick, meat, "throbbing, engorged flesh," etc. And if you want to be funny, just call it a "meat packing unit" like I do.
Same goes for the female counterpart. I can't bring myself to use pussy. More interesting: entrance, channel, lips, folds... Dirty: slit, slot, hole, "tender, rippling, quivering
innards... Funny: meat collection receptacle. ;3