You have to look at firearms like they’re tools, because they are. Decide what job is paramount to your prepper situation and get the firearm that’ll be the best fit for that job.
Not knowing what your needs are, what your budget restrictions are, and what legal restrictions you might face, these are my recommendations:
If your primary concern is hunting animals for food, look at getting a couple of combo guns. In that category I’d recommend a .22LR over .410, and a .308 over 12GA. Baikal, a Russian manufacturer, makes guns in those calibers/gauge. Savage Arms also makes a combo model (the Model 42) in .22LR or .22WMR over .410. Break-breach rifles are simple, reliable, and easy to clean. You can also carry them loaded fairly safely by carrying it in open-breach position, closing the action only when you close in on your game. With two firearms you have four rounds that should cover most game. You’ll have .22LR/.410 for small game and birds, and .308/12GA for large game and birds.
If protection is your concern, and your government allows it, look at getting a shotgun, and a rifle in the increasingly popular category of scout rifle. For the shotgun, I’d go for a 12GA in the pump-action family. Make sure you get a shotgun that is threaded for chokes – like the Remington 870 Tactical – so you can also you use it as a bird gun (some tactical shotguns aren’t threaded for chokes). In the scout rifle range, there is the Ruger Gunsite Scout (expensive, especially spare mags), the Mossberg MVP Patrol, and the Savage Model 11 Scout. All those scout rifles are .308-caliber, short-barrelled bolt-action rifles with 10-round detachable box magazines. Each is also equipped with a Picatinney rail for mounting long eye-relief optics. The MVP Patrol is also offered in .223 Remington. In Canada you can’t get the MVP Patrol with a 10-round magazine (it’s five rounds max). I believe that is because that rifle uses magazines from restricted rifles in Canada, so you can’t have them here.
Regardless of what you buy, you should have at least one .22LR in your collection. My favorite is the Marlin XT22TSR. It’s a bolt-action rifle with a tubular magazine. It’ll eat .22LR, .22 Longs, and .22 shorts, but not .22 Magnum.