Yes, the ALS Association is an amazing organization with a great cause, but we know the real reason you are watching all those ALS ice bucket challenge videos — the hot dudes. Some of Hollywood's best-looking men have taken part in the challenge, and quite a few of them have decided to take on the icy water while either showing skin or wearing shirts that suddenly turn very sheer once they've gotten wet. We bet they know exactly what they are doing, and it's definitely piqued our interest! Keep reading to see the hottest ice bucket challenges, and don't forget to check out the very best celebrity versions of the viral trend. To get involved in the cause, go to ALSA.org.