Okay, since Mickactual did such a good job covering the East Coast, I'll give my impression of the West Coast.
Los Angeles does, indeed, have a few bath houses left. The clientele tend to be a bit younger and better looking (on average) there, but the San Francisco Bay Area has them all beat, hands down. Why? One word: Steamworks.
Located in Berkeley, CA (although they have others in Chicago and San Juan), Steamworks is the best bath house I've ever been to. If they were ever to ban me, I'd probably walk into the ocean and kill myself. The staff are all extremely nice, they never expect a tip (although there are tip bowl, and they're usually full). The place is extremely clean and well run, and no one EVER gives attitude.
A six-month membership is $20, and a locker is $13 each time you visit. There are regular rooms (no tv) for $20, and tv/video rooms for $25. They also have a few large rooms complete with sling, etc., for you kinky dudes (not my style). If you're just visiting, they'll sell you a one-time pass (something like $5.00) and then you just pay admission like everyone else. That keeps their "private club" status straight.
The clientele varies. Sometimes it's a very mixed crowd. Being so near to SF, there's a surprisingly large percentage of Asians, of course. Also, a good many older, overweight guys hang out there because they're retired and horney. Even still, there's no shortage of hot guys with big cocks. I get my nut about 80% of the time I go there, and I've very picky about who I fool around with. They need to be cute and hung to get my attention, baby.
They have a hot-tub-style pool, a large steam room, exercise equipment (which a few actually use), and a large back room where there are booths, a raised blow-job platform, and lots of places for privacy in the dark. The rooms are pretty darn small, but then I'm not renting it to entertain guests, so I don't mind. Two towels are given at the door, and you can get as many extras as you like, free of charge. (They tried charging $1.00 per extra towel, but that didn't work out so well. Now they're back to the courtesy of free towels, and we're all happy again.)
There are large screen tv's all over, and a projection screen in front of the pool playing porn. The place is open 24/7/365, so you never need to worry about schedules or any of that bullshit. If you're horney, Steamworks is there for you. (Of course, your chances aren't that great if it's 4am on a Monday or something, but still...they're always open just in case! LOL)
The best times to go are Thursdays (it's lights-out night, complete with glow-in-the-dark necklaces to help you get around in the dim lighting), and/or any time there's a holiday or a big event in SF (like during Pride, Folsom Street Fair, or Halloween...gotta love them tourists!).
If anyone is planning on going and has any questions, pvt. me. I'll be happy to play welcome wagon! : )