I added Capetown to my list of places to visit.
As for Germany, it sure is great in the summers ... but unless you plan on living at the party scenes (as mentioned) you'll be spending a lot of cash. Europe is quite expensive.
But except for that, the trance scene in Europe is outstanding!
South Thailand is also very good, Koh Pha-Ngan (big surprise) has a party every day at times. Entrance is usually 200 bath, about $5, and that includes a free drink.
Just be sure you go there late, maybe 5 or so in the mornings ... earlier at night the parties attracts too much drunk tourists that are more in to getting drunk/high then the actual dancing.
I don't know much about the rest of Asia but you should find out considering it's very close for you.
Austrualia seems very fun as well, maybe you can tell us some about it =)
As for me I'm in Sweden, in the summers we have ok parties here as well but the cops always try to shut it down so you might end up at the police station for a few hours ... something you don't have to worry about in Germany for example.
Anyways, gotta stop rambling, good luck on your travels!
Peace,
Dario