It's boring and predictable but Lennox Lewis had a hell of an uppercut. It took the heart out of Holyfield and Vitali after they got hit with it. George Foreman in his comeback trail also threw some sickening uppercuts in his time, Gerry Cooney was one that sticks in my mind.

I think the uppercut is an under-used weopon, I have no idea why people don't use it more often.
You see in fights all the time where people are so open to uppercuts, I'm screaming at the TV sometimes and they never throw them.