Mt High is a not too steep mountain with a pretty decent terrain park, big crowds, and inconsistent snow years (hence the insane amount of snowmaking, like everywhere in SoCal).
It's close as fuck to LA, but it's also kinda not hugely awesome compared to a lot of places.
Mt. Baldy is the best terrain in socal, but is south facing, so shit gets slushed out quick once the sun does pop.
Big Bear is probably the best bet as far as everything all around.. and has the best views/elevation and such, but it's a bit further than the rest of LA.
If you're moving to the LA area in the spring, then hope for a good year.. most of it's done by march in most seasons, and you're stuck hitting the road for 6 hours to make it to Mammoth - which really only sucks if you dont have a good ride-share situation.