I think you nailed it pretty much with what you said. Havasu for partying, Powell and Mohave for the family. Although Gasoline Alley in Mohave is a pretty darn good party spot. The only thing to really watch out for on Mohave or Powell is the wind. Otherwise they are both incredible.
Other lakes on my top 10 California lakes are (not in any order)
Don Pedro
Tahoe
Bass Lake (for the scenery and lake front houses)
Pine Flat
Delta
Never been to Shasta but I hear its awesome too.