Each city has its merits but I tend to veer towards Amsterdam - I could say it's because it's a nice compact place to get around with some fabulous architecture but actually I go to drink really good beer and smoke excellent weed.

Paris is nice, too, but the main drawback is that it's full of French people who ... how shall I put it ... tend to be less welcoming that the Dutch. However, on the plus side it does have very good transport links with London which, of course, is better than both Amsterdam and Paris put together.