I've got a couple:

WJ Jeffrey SxS .450 No.2 Nitro Express; & a
Tikka 512 SD U/O 9.3x74 mm Rimmed.

Hopefully end up with an additional barrel(s) for the Tikka.

A Greener Empire 12-bore is a future project. Another future project is a modern scoped .500/.416 SxS, a rifle I deem will be truly useful.

Some of the guys here have truly inspiring collections but may be reluctant to tell online. Myself I am only starting and have vicious dogs and Fort Knox as storage.