Oh man, I probably shouldn't write them all down, because that's just acknowledging the problem.
Mamiya 645 1000s (rarely used)
Mamiya 645 Pro/TL (used more often than the 1000s, and I have 4 of them)
Mamiya C220
Mamiya RB67 PRO SD (most often used MF cameras I own, I have 3 of them)
Goodman Zone
Bessa I
Bessa II
Bronica S2A (rarely used anymore, don't like dim viewfinder)
Brownie Hawkeye
Yashicamat
Kowa Six (own 3 or 4 working ones and a bunch of cannibalized others) (really enjoy using the Kowa Six)
Kowa Super 66 (2 working ones) (enjoy using but the removable film backs are huge)
Hasselblad 500C (early)
Hasselblad 500CM
Holga 120N (several)
Holga 120 Pinhole
Holga 120 Pan
NOON 612 Pinhole
Fuji GX617 (love using it, but don't use it often enough)
If I had to narrow down what I had, I'd probably keep 1 of each aspect ratio, and those would be the following:
6x4.5 = Mamiya 645 Pro TL
6x6 = Holga 120N
6x7 = Mamiya RB67 Pro SD
6x9 = Bessa II
6x12 = Holga 120 Pan
6x17 = Fuji GX617
Jeremy