After reading through the replies, (without doing an actual count; wouldn't want to waste any more work time on that) I got the impression the leading contenders are:- Those special guitars (write in your dream guitar here). - Mandolin - Hurdy-gurdy. (I liked the Hurdy-gurdy website too.)
I second the comment by Greg Stephens about the fiddle. However, just because one took it up 20 years ago doesn't mean you can play it. It just means you're twenty years closer to actually being able to play! (You made me smile though! Maybe all I need is another 13 years here.)
And SharonA has hit on another problem…space to house all these instruments.
Sorry not to comment on everyone's choices…but I'm happy to know people are out there who dream about playing all these interesting instruments.
Zhenya