Im not sure where I would recommend. Many of the saunas can be difficult to navigate, uneven floors, tight winding stairways and a lack of adequate lighting. If you have no mobility issues I would suggest Krubb or Sauna Mania. Krubb is over 4 floors, so lots of steps, but it has a nice bar on the top where you can have a drink, a dip in the spa and check out all the talent. Sauna Mania isnt on as many floors and is a bit more rough around the edges, but it is closer to the gay area so gets more western tourists, so you wont feel out of place there.
 
	Honestly there are so many to choose from, its not as simple as the old days with Babylon/everywhere else. I havent even touched on the huge number of gay onsens that have sprung up in recent years. 
 
	 
 
	WhTever you choose I hope you have a great time.