I only come to Amsterdam once in a while (a few times a year to visit clients, less than once a year to 'visit')... So I don't know many interesting spots apart from this shop which was at least fun to visit:
http://www.platenkoning.com/games.html And I don't know about Amsterdam, but in the rest of The Netherlands, a real arcade is extremely seldom nowadays...
You must have been the first tourist though who didn't ask about drugs first
Arnoud