I'm no equipment expert, but have enjoyed owning and using a rather large number of MF cameras over the last few years. I started getting into it after embarking on a monumental journey of digitizing my dad's old negatives, shot mostly on a 6x6 TLR. When I discovered that used MF cameras (mostly of Japanese origin) can be had for pennies on the dollar I got the bug and before I knew it I had a rather large collection, all of which I enjoyed using extensively. That's when I decided to share what I knew about them on my web site, Chemical Cameras. It was a thoroughly enjoyable task. But alas, I eventually came to the conclusion that I would rather own just a few cameras that I really loved so I began selling them off and getting/keeping the ones I really wanted. Now I am down to four really nice ones (plus a couple junkers with no resale value in the closet). So I would be happy to contribute whatever knowledge I have gleaned in the process. For the record, the four I settled on are as follows:

Pentax 645n
Mamiya 6
Fujifilm GF670
Pentax 67ii