The best music in London is played at The End and Fabric. Both are excellent, but be careful to check the line-ups as there is quite a bit of variation in music policy at each (fridays at fabric are always breaks/d&b, the end also have alot of d&b/breaks nights).
Peach at Camden Palace is a funtime full on ravey experience.
The Cross is uslally too packed and you get pushed around too much for my liking.
The fridge in brixton is best for hardHouse. Ministry is fine but i dont like going there in principle (it's run by tossers). There are often great psy-trance parties at EQ warehouse in Stratford or hackney way.
I concur that london clubs are full of winkers till about 2am.