I've been playing banjo for most of my life since the sixties. I've now got 4 five strings:
An open back Lo Gordon (Cedar Mountain) banjo with wooden tone ring (the Dwight Diller model) with a lovely mellow woody tone.
A. open back Bart Reiter Tubaphone with a brighter pleasant tone, lots of volume.
A Deering Sierra bluegrass banjo with resonator that I was lucky to find in an auction for a lot less than I would otherwise have had to pay. Very loud bluegrassy sound, but can be played much quieter. Too heavy for sessions, though.
An El Cheapo Korean banjo that I can dismantle to put in my luggage for skiing holidays.

Other instruments:
2 fiddles (standard and cross tuned) that I've been trying to play Old Time music on for 10 years with mixed success. I get it out in sessions when I'm the best Old Time fiddler there (very rare).

A cheap electric fiddle which I can practice quietly on after midnight without plugging it in.

An old Yamaha FG340 guitar that I occasionally pick up and strum.

A Roumanian flat mandolin that I've recently replaced the tailpiece on. I find that picking it is harder than bowing the fiddle for the same tunes.

A John Grey banjulele that mostly hangs on the wall.

A few blues harmonicas in different keys that I used to play much more than I do now.

A couple of whistles (half a dozen old irish tunes I've known for years)

A couple of Jaw's harps.

A stone jug and couple of kazoos - you never know when they'll come in handy!

Cheers
Ray