Top of my list would be my Gibson Super 400 - a 1958 CES, serial #A-28256. I should never have parted with it, not even when I sold it briefly in the '60s and certainly not once I'd got it back! I assume it's still in the Hard Rock's inventory.
(I know there are better archtops, but none would have the sentimental value of my one. And no, I probably still wouldn't play it before I picked up a Tele.)
Second: I'd like ANY of the Everly Brothers' J-200s; one of the all-black ones, the grey ones, or the black with white 'guards. Albert has Don's - Phil's black-with-white is still in his family's possession.
Third: This is hard.
A) Any prewar Martin 000-45 (14-fret version)
Or:
B) A brand new Emmons Resound, 9+9, black with a red belly. I can't get sentimental about old steels, but these new ones are works of art!
I know that's a sneaky 'four'. Sorry.