I have had a half dozen mixtes pass through my hands (and still own 2 of them), all but a Motobecane were Japanese built, and while not made of high-end tubing were very nice to ride.
I still have a Bridgestone and a Univega, and have sold a Fuji, a Nishiki, and a Centurion. I don't think you can go wrong with a vintage Japanese bike.