Okay so assuming you don't start on the enemy's Jungle, you have 4 options:
Red
Blue
Wolves
Raptors
Not many people start wolves of at all, so this really just leaves Red, Blue, and Raptors.
Raptors are actually surprisingly easy to clear level 1 should you and your Mid Laner have level 1 aoe. Rengar's Q for example is fantastic at this camp and Raptors is actually one of the more common starts for him in high level play.
Blue is an absolute necessity for some Junglers, so it's obvious when they must start there.
I've noticed that, especially for Ganking Junglers, taking red is a signal that you're ready to gank. Most people won't start red unless they're planning to go for an early gank, just planning to farm, or go for cheese.