I currently have a Pentax 67 with 4 lenses, Hasselblad 500c/m with 80/2.8, Pentax 645 with 2 lenses, Bronica ETRSI with 4 lenses, and a Bronica S2 with 2 lenses.
I think for what I paid, the best bang for buck is probably the Pentax 67. I have the body, WLF and unmetered prism, 45/4, 90/2.8 (late), 105/2.4, and 200/4 (late), and I think all said and done, I paid less for the entire kit than the $800 I spent on the Hasselblad and 80/2.8
Of the group, the Hasselblad is quickly becoming my favorite.
The Bronica ETRSI kit is my most used and is great bang for buck. I have the body, WLF and unmetered prism, 120, 220, and 135W film backs, and 40/4, 50/2.8, 75/2.8, and 150/4. If you take the 135W out, I don't think I have $500 into the entire kit.
The Pentax 645 is great as it can be used basically like a huge 645 P&S 🙂
I actually really like the Bronica S2 and especially the Nikkor-P 75/2.8. They can be great cameras if working properly and they can be found for under $200 with the 75/2.8