My favorites:
Nikon F (own 3)
Nikon F2AS (own 3; with Motors)
Canon F1 (own 2)
Canon New F-1 (own 3)
Olympus OM-1 (own 2)
Leica IIIf (own 2)
Nikon F100 (own 2)
All functioning and being used at the moment.