The best parties are those that I don't remember where they happened :sick: . Mostly WG parties hooking up with locals, and then going to clubs, bars, weird places.
My favourite spots were Club der Visionäre, Bar 25 (afterparties there were absolutely mind blowing), Cassiopeia, Berghain, Rio, Watergate (somewhat poshier, but IMO the best club I've ever been to), Tresor (for the big nights out only). The Golden Gate is a small club, but very friendly with just great music (bit too much drugs to my liking, but it's not unsafe).
Then there are small places near Ostkreuz that would just open for a couple of months if not weeks. I guess some of the places listed will be closed by now (I think the Rio closed while I was still there) and other cool places opened.
I found the best way to have fun is just to talk to people, find the kind of spots that you like and go from there.
On sundays, I'd just hang out in one of those Raumwohnung-bars with free WiFi (no internet at home), sipping on a Club Mate...
Aaaaah. Happy times.