I live just south of San Francisco. I have only skied Mammoth on July 4th weekends, for the simple reason that the mountain pass closures make travel to Mammoth impractical during the year. Effectively, and assuming decent weather, you need to drive four hours or so to Tahoe, then head south for about the same distance to get to Mammoth. I love Mammoth, but there's no way I'd drive past Heavenly and Kirkwood, let alone Alpine and Squaw, to get there.
Some information about what you like to ski would help suggest Tahoe areas. CirqueRider's questions are a good start.
South of the lake, Heavenly is known for its groomed runs and its lake view, and Kirkwood is known for its rugged terrain and lack of convenient lodging or access. After you pass Sacramento/I-5, the drive to either of those is primarily on a two lane highway, which my wife hates doing during the summer, let alone the winter, so we've only done one south trip.
On the north side of the lake, the major areas heading east from San Francisco on I-80 are Sugar Bowl (longest-lived resort in the area, high base, nice terrain, but not much vertical), Squaw (largest north lake resort, full-service base area, "extreme" terrain, prices and attitude), Alpine (often considered the Alta to Squaw's Snowbird, with similar terrain, less attitude and cost, but with few lodging options at the base), and Northstar (known for groomers and pipe/park, more of an intermediate hill than Squaw, Alpine, or Sugar Bowl, full-service base). I'm partial to Alpine, where my kids are on their third year on team and I'm a patrol candidate this year, but the lodging options at and near the base are more difficult for weekend trippers (which does tend to keep crowds mercifully small).
The best basic summaries I've found of the different resorts are here
. You can also search around here.