I'd just be happy to shoot some of the dozens I have that I have yet to. If I have to narrow it to three of them, I guess I'd pick my N-PAP, my Romanian TTC, and the 67-1 I recently got. Okay, that last one technically doesn't count, I guess, because I was issued one back in the day and shot the snot out of it. So, maybe number three would be my Winchester 94.
I don't really aspire to hold any gun just for the sake of holding an example of that model. It would have to be a specific gun that, in itself, had some historic significance. Even a war-period rifle that would likely have been hefted by a soldier in defense of country, who possibly took, lost, or both, life while carrying it, evokes a feeling of honor (I have a 91/30 that meets that criteria, and have never shot it, but I have shot another one, so I didn't mention it in the paragraph above.)