Before I answer, I have to say this..... READ THE STICKY!! thats what it's there for.
Ok, for Hunters, the easiest leveling build there is, is the BM tree, which also happens to be the top DPS tree. I say this because it gives you far more survivability than MM, and I don't know SV well enough to say anything, but I think it is more of a "Utility" tree than a Survival tree, but thats just me.
It gives you the fastest soloing potential, most group DPS and the a anti-CC button once you hit lvl 50 and have specced right.
You get better damage, a better pet, which means better tank when soloing, and trains you for the best DPS tree for end-game, if you play it correctly.
If there is anything you didn't get from this thread, read the stickies, the answer is there, I promise.