Mostly it depends on what you hunt and where. If you just plan to hunt deer and smaller game inside of 200 yards just about any bullet and caliber will work fine. It's when you start chasing the tougher critters that bullets make more of a difference.

Elk, Moose, Bears, etc. really should be hunted with a premium bullet (Partition, Accubond, Interbond, A-Frame, X-bullet). They are designed to hold up better on these bigger, tougher animals and perform better.