What do you want to ski? The great part about Tahoe is every mountain is really different with regards to what people like and ski.
I ski kirkwood which is steep and the park isn't anything to brag about. Heavenly/northstar are pretty simli9ar in the sense that they're both flat and they have good parks. Squaw and alpine have a little bit better terrain (I mean a little) but I think it loses the overall battle with kirkwood for steeps and powder because of crowds.
Mt Rose and Sugar Bowl are ALWAYS underrated and probably the best of everything with regards to steeps and decently good parks.
Boreal right now is a waste of time IMO since most every mountain has their parks up and running.
Squaw and alpine are crowded, heavenly's flat, lots of bay area people ride Sierra, but it's still pretty rad.
I guess we need to know what you're wanting to ski. When I say steeps I mean The FWT is held at kirkwood...