Okay, last night I had this IPA that was flat out delicious, but I swear it knocked me on my [naughty word]. Seriously--I was bouncing off the walls of my house after ONE 12-oz BOTTLE. It's called Dogfish Head 120-minute IPA. One of the most complex flavors I've experienced in an IPA and had it not put me onto the floor, I would've run out to the store and bought a six-pack. As it is, I just can't see making a habit of something that strong.
EDIT: I just looked it up: 20% ABV. So yeah--proceed with caution.