You might want to check out Mazzo - a superb club in my opinion - the music varies from night to night but the last time we went to Amsterdam the music on the Saturday was really good trance.
As Pacha4life mentioned, Escape (Rembrandtplein) is a really god nightclub, more so if you catch the Chemistry nights.
It might be worth finding out whats on at the Roxy Amsterdam as although we didn't go, we did see flyers for some good loking nights there.
Also you could try Melkveg as Layo and Bushwaka play here now and again
http://www.melkweg.nl/home.htm
Hope this helps a bit
Mark