My all-time favorite is a waterfall or gravity bong. Tiny hits get you fucking high! Next up is probably a bong, followed by a joint. Blunts are good, I suppose, but I never have enough bud to smoke them. Chillums and one-hitters...I'm not a big fan of, although the onie makes driving adventures more interesting. Vaporizers kick ass, but I've only smoked a legit one once, so I can't really comment on how they stack up. Bubblers and whatever I left out...I never hit them, so they're not on my list.
So my true favorite way is with a gravity bong or waterfall. If you've never hit one, you really should. They get you goddamned high!