Which are the best cities in Europe for a group of 18 year olds to visit?

So, me and my friends are going to do the Inter Rail these holidays, and the trajectory we were planning was Lisbon (from where we set out) ---> Barcelona ----> Civitavecchia--> Rome --> Venice ---> Greece (still don't know where) ---> Budapest ----> Prague ---> Berlin ----> Amsterdam ----> Brussels ----> London ----> Paris ----> San Sebastian ----> Lisbon. We have 22 days to do it. Recommendations for cities to visit are welcome! Small cities and towns are also OK (as long as they have a train station. We are mainly going to party, don't suggest cities with based on cultural/historical stuff... Nice cities (aesthetically pleasing) with fun, young and hot people would be the best.

Public Comments

1. AMSTERDAM ALL THE WAYYYYYYYYYYYY!!!!!!!!!!!
2. Spend the WHOLE time in Paris, it is by far the best city in all of europe!
3. amsterdam duhh its like the party capitol of the world
4. Hi, Amsterdam definitely, and you'll find Prague to your liking I'll bet too....
5. I will agree and say Amsterdam - but take pictures and video because you aren't going to remember anything!! OH bty - Don't watch the movie "Hostel" before you go.
6. As a young londoner, i recomend soho and the 02 arena and if you want a mad mad rave try to go to brixton mass in london, very good places to go, loads of hot young ladies, but be warned london is a very very expensive place. and a word of warning, dont stray to far out of central london, it isnt very pleasant, and theres alot of crime. and if your visiting greece, may i suggest a place called kos. very lively,
7. It would be useful to go somewhere where at least some of you speak the language.
8. I don't wanna burst your bubble, but Greece is WAAY out of the way from all those other places. Just thought you'd wanna know you might be able to save some time if you didn't go there... Munich I've heard is pretty cool, though I don't know if its a party place, or a "we drink a lot of beer" place. Also Madrid might be fun to hit on your way back, I hear they party till about 6 a.m. there on a regular basis. Perhaps some French Riviera, like Nice or Monaco? But out of your answers, I've heard to DEFINITELY hit up Budapest and Prague... Also Amsterdam (duh), and anything in Spain...