I'll second Jim's recommendation. I use a Bronica S2a, and it's an amazing camera. Fully mechanical, built like a tank, razor-sharp Nikon lenses...it was my first MF camera and I still use it quite often even though I have much more technologically advanced systems in my arsenal.
One thing to be aware of with the C/S2/S2a Bronicas is a problem with the ground glass foam deteriorating, which throws off the focus of the camera. The fix is very easy, and is detailed at Dead Link Removed - it took me about 10 minutes to fix mine when I got it and the focus is still spot-on years later. (There is a lot of information about the Bronica systems at Dead Link Removed)
The Bronica system included lenses by Nikon and Komura, a bellows with tilt and shift features, a portrait lens with its own leaf shutter for flash synch at any shutter speed, a couple of different finders, and backs for 6x6 and 6x4.5. The camera has a focal plane shutter so most lenses only have flash synch up to 1/40th of a second, but the portrait lens with the leaf shutter fixes that if you need it. The focal plane shutter means that you can mount any lens on the camera that you can hack together a mount for...I've put everything from cheap plastic loupes to large format lenses in front of my S2a just for fun.
All in all, it's a very capable camera with many options available. You'll learn as much on one of these as you will on any MF camera. It doesn't have the cachet of a Hasselblad (and there are a lot more Hasselblad lenses out there than old Bronica lenses), but a starter system can be had very inexpensively. The cameras still be repaired if necessary.
Probably the best recommendation I can give you is this: When I was headed to Europe last year, I took the Bronica with me. I felt very confident that it would be a workhorse and that I wouldn't have any problems. I wasn't disappointed.
Best of luck with your decision.
Dave