Most of the gyms in San Mateo county are fitness centers; not hardcore. Even the Gold's Gym in San Mateo (Hillsdale, off the 101) is set up like a fitness center. I went in there over a year ago when they opened and only 1 squat rack, and the dumbbells only go up to 100 lbs. Plenty of machines and 2-3 cable systems (pull down, row, cross over, etc). Perhaps they've added more equipment since then; check it out. Maybe the Mountain View location is better; never been. The 2 in SF are too far.
Never been to Bally's (South SF), so no opinion there.
There's a Powerhouse Gym in Redwood City, but I've never been.
I'm more familar with 24 Hr Fatness. On the peninsula, I've been to the San Carlos, San Mateo, Daly City, Pacifica, and Ocean locations. Pacifica was too small, Daly City was a dirty, hot pit, and San Mateo was a fitness center/meat market (free weights upstairs so you get yelled at everytime you drop the heavy weights). I currently go to San Carlos. 1 power rack, 3 squat racks, 3 complete cable cross over stations, dumbbells up to 140 lbs, plenty of machines, and plenty of Hammer Strength. The plates aren't the newer Iron Grip design, but they still work. Sauna, but no pool. Plenty of cardio machines (segregated from the weight lifting area). I've seen a few people use chalk (keeping the area clean, of coarse), bands, and board presses. Never seen anyone try to bring chains in though.
If you want hardcore, your best bet is to live in the east bay, so you can drive over to Diablo Barbell in Concord.
Hope that helps.