Hmm... I've got a few. The first would be when I was about 15. I was on my own in my house at night and found 8 cans of beer in the fridge. I drank them all in the space of about 2 hours, blacked out, and when I woke up there was a vomit trail leading from my mouth off my bed and onto the floor. I think I somehow managed to get sick in my sleep.
The next one was last summer. I was at a friend's 18th birthday and decided to drink a full 700ml bottle of Jagermeister straight. Worst hangover I've ever had.
The most recent was at around Christmas. I was at a debate being hosted by one of my college's clubs and my friends and I decided to play a game where you had to take a drink every time a certain word or phrase off a list was said aloud. I brought in a naggin of vodka with me (I'm going by the colloquial name for that size bottle, I've got no idea how much is in one, about 400ml I think) and it was empty by the time the second speech was finished (about 10 minutes). At the post- debate reception, I had 4 glasses of wine and 5 bottles of beer. I blacked out after that, but I'm told I fell asleep one on of the couches in that room and had to be removed by the security person. I woke up in my bed in my flat, (I assume I walked because I didn't have any less money than I had had before I left the previous night when I checked my wallet and I walked to college), and there was vomit EVERYWHERE, including all over my roommate's desk and clothes. I had to miss 3 hours of the next day's classes cleaning it all up.
So on the whole the last one was probably the worst.