Almost anything that's old, especially tools. I don't use them, I've got new ones for that. Tractors, really nothing in particular anymore, there's too many things that look interesting to me. I've got old cast iron wheels from tractors, old dinner bells, old hitching post heads [cast iron], old bird houses. I don't care much for furniture, but I do have an old AM/Shortwave radio in a console with a 78 rpm turntable, and some albums from the 30 and 40's, Sons of the Pioneers, etc. Pipe and Drum music, even have a stupid Don Ho Christmas album, it really sux. A few vinyl rock albums, I had all the Stones albums from the 60's.
There's just too much interesting stuff out there to be stuck collecting only one thing for me.