Will just add my .02 as well.
.22 rf no one should be w/o a decent .22 rifle and while I like real nice rifles such as the Marlin .39, or the Ruger 77/22 and the like, if I were limited through budget or some other reason I would start with a little Marlin 60 or other variant bought used through a gun or pawn shop. They can usually be had for $60 or less and as such are simple to buy 3 or 4 of them for the price of a "nice" rifle. They will eat just about any ammo you want to feed through them, will give you quite acceptable hunting accuracy, and for the money they are just darn good guns. Buy a couple of cheap fixed 4X scopes and you are ready to hunt all the small game you want (as well as outfitting any other folks around to help you).
30/06 bolt rifle (any major brand, remmy, ruger, Mossy, etc), with a decent 3 x 9 scope. The reason for the 30/06 is simply ammo availability. It is easy to find ammo for it ANYWHERE and if you want to stock up on ammo, the surplus market is better for 06 ammo than anything else out there currently. As has been stated before the 06 will will anything you need it to inside of 500yards and if you know how to do your part, it will go out pretty well even a little further.
As for my Home defense rifle well it would NOT be a rifle. I would buy a good used 12ga (Mossy 500) with an 18in barrel with plenty of 00 buckshot and slugs. I would also invest in a a scoped rifled slug barrel to use the shotty as a second hunting rifles and a cheap 28in barrel to use with light shot for small game if needed. BTW in many cases a good used shotty can be bought for $150 or less, giving you the option to add more than one to your collection.
Now limited to 3 "rifles" that is what I would do.