Great thread, guys! I like the mix of suggestions. While I'm a big 1911 fan, I'm not sure it would make my Top 5 list unless the premise is a mix of guns to have in the "collection" or guns needed for overall usefulness. Assuming it's a mix of both, mine would be, in no particular order:
Shotgun - 12ga pump 3" chamber (can shoot high or low power, & have extra barrels)
Revolver - 45 Colt (4-6" barrel) can load high or low or use snake shot hiking
Semi-auto pistol - 45ACP high-capacity polymer type
Rimfire Rifle - 22Mag / 22LR Bolt-Action (Marlin)
Centerfire Rifle - 45/70 Ruger No.1 or a lever-action depending on where you live and if really need a fast second shot. Can load high or low power, too!
Only need cleaning kit for .45cal and can minimize primers needed and "could" use Sierra load data to substitute a 45ACP bullet into 45Colt for plinking purposes. This list covers tactical and self-defense, hunting anything in N America, plinking and small game, minimize inventory or loading gear, and easy to adapt to young and older shooters for recoil.