That's a really hard question for me to answer.
I really liked the first pistol I ever shot, a WW2 Luger in 9mm(I was six). Or, maybe the first gun I ever owned, a Ruger Blackhawk in .357(I loved then and now, the "Old West").
Or maybe my Delta Elite because it's so purrrty!(And I think I'm addicted to 10mm recoil!)