Best places in Europe to spend a 21st birthday

So I'm thinking of things to do for my 21st birthday which is in November. Two friends and myself will be going somewhere in Europe for about 3/4 nights over the weekend. I'd like to go somewhere with a good nightlife, a bit of culture and lots of things to see and do (that you can do in winter as well)

Any suggestions?

Amsterdam.
And no, don't think that I'm being a deviant, I know what it's famous for etc.
But it is a real nice place, definitely full of nightlife, culture and history.
If you want somewhere more historical and are into the Arts then try Prague or Vienna. There pretty in the Winter, and have skiing and ice-skating all year round too.

Thanks for the suggestion
I have been to Amsterdam twice and love it, did originally want to try somewhere different but I'm wondering if we should just go back to Amsterdam because we know it'll be good!
Is there anything in particular in Amsterdam you would recommend to do that I might have missed out?