If you're limiting yourself to five guns then versatility is the name of the game. If we're talking Canada-legal and plausible for a regular guy to get hold of and actually use...
1/ Ruger 10/22 - .22lr. Small game hunting and plinking. Almost limitless ways to customize, and the only way to run hi-cap mags.
2/ Glock 17 - 9mm. Everybody should have one good handgun. Personally I hate the ergonomics on Glocks but these things are everywhere and parts/accessories will never, ever be a problem. 9mm has served many armies well enough for over 100 years, and much cheaper to shoot.
3/ Remington 870 - 12g. The ultimate Swiss Army Gun. Cheap, rugged and if you swap out barrels/chokes you can use it for everything from small game to wingshooting to big game to home defense.
4/ Mauser-based bolt gun of choice in .30-06. The strongest, most reliable action chambered in the ultimate do-it-all caliber. What else has bullet choices from 55gr sabot accelerators to 220gr moose-slayers? A well-tuned .30-06 can do everything from varmint hunting to big-game to long-range target shooting, and do it well.
5/ AR-15 - .223. Like the Glock these are everywhere and accessories will never be a problem. 10-round LAR griz mags and cheap ammo for the inevitable rise of the Zombpocalypse we all know is just around the corner.
or if you're not the paranoid sort...
5/ Mauser-based bolt gun of choice in .375 H&H. All the versatility of the .30-06 but on a bigger scale, for use on anything that you might feel under-gunned going after with a .30-06.