In center fire: Glock 17, 21 or a Kimber 1911 because I like Glock/1911's best of the new and best of the old ( just my opinion no one freak out!). Caliber choice is because I feel that 9mm Luger and .45ACP are the best calibers out there. Tried and true in combat over many wars, nothing speaks to effectiveness like body count.
In .22- Browning Buckmark because it is easier to diassemble than Ruger (like alot easier) and it is a tack driver. It also will eat any ammo even Remington "Yellow Jacket" which most autos do not like. Don't use CCI stinger it is too potent and is specifically mentioned in the Buckmark manual and also in the Ruger Mark 2 manual.