Those Rolleiflex are terrific. It's even better to have the history of the camera intact. I was actually contemplating buying one not too long ago. I really think it's worth while trying all the formats that are available.
I really like the various Mamiya Medium formats, but they don't allow for a polaroid back, which is something I value. I'm starting to work in a studio more, and find the polaroid back lets me get thimgs just so on the large format. I love it's flexability, and resolution.
Here's what I have, other than the 30D I'm shooting with (just a mindless robot, no sould like the rest) :
And lastly something I'm just starting to play with. A Lentar Super 8. Classic, and produces striking results. Especially when you slow down the FPS. 12 is quickly becoming my favourite: