I have been to Chariots in Shoreditch a couple times and really like it. I loved sitting by the pool and watching the hot guys dive in the pool and swimming naked. They also have two showers and two hot tubs. For me, a big time voyeur, it's great because you can see so much there. I would highly recommend it!
You might wanna check out the naked club 'Nudity' in Vauxhall, London as well. Only been there once since it's only twice a month and I only get to London once a year, but it was awesome. I so wanna get there on one of their foam party nights. In a lot of ways I would prefer it to a bath house. Everyone in naked, no towels allowed, which is great for cock watching, and it is incredible watching all the sex going on. In that way much better then a bath house.
I went to the Vault my last time over in May 2011 when I was over for the Wedding. They have naked nights and they are pretty cool as well. The only problem with naked clubs is that there are no showers to clean up in afterward. lol