I am going back. Someday. Sapporo is a pretty big city. Lots of things to do around there.
The tourist onsens aren't that bad.Really, anything that's an onsen and not a sento is probably going to be good. Well, I say that, but I went to one that was covered like a greenhouse that looked like it hadn't been cleaned in 30 years. Anyway, there's one town known specifically for onsen which has hotels built specifically around them. Really, really, fancy and amazing. These hotels usually have day passes (something around $20 worth) and it's great. Some have like 8 or more baths. Different temperature hot ones, a cold dip bath, a big outdoors bath, saunas. Aaaahhhh. I could use one right now.