PDH suggested the older Mamiya 6. I have one and it isn't bad, but I agree that vintage folders can be somewhat of a crap shoot. I ended up buying a second one for parts, combining elements to get the cleanest lens I could and then getting a hood for it and the results were much better than when I first got it. But stilll, I would strongly recommend the New Mamiya 6. It is superior to the old one in almost every sense. The only trade off is that it is a little bit bigger.
It has exchangeable lenses but there are only three so it isn't one of those endless money pits! In particular the 50mm WA is exceptional.
It is very compact, even more so than the 7 or 7ii because the lens collapses into the body when not in use. I think it's lighter than most TLRs and easy to hold/operate.
The ergonomics are very good.
The view finder automatically adjusts for each lens and has parallax comp. so no need for external finders.
It has a built in meter if you want to use it, but also can be used in manual.
The build is much more robust than any folder.
I have been very happy with the results!
If you really want to go with a folder I would recommend the Fuji GF670. It's pricey but has the wonderful advantage of being able to shoot 6x6 or 6x7 without the hassle of changing film backs. And the optics are second to none!