The oddest finish, anyway....
is the fully case hardened pistol I saw recently, either here or on 1911 forums.
Not bad, but rather odd to my eyes.
By the way, gold is a very functional finish for a sidearm. It wears well (think of all the replacement teeth out there) and just flat does not corrode.
My favorite is the old Smith & Wesson deep blue. And I'm partial to scroll engraving. Gotta have wood grips.