Whatever you've got is my favorite, as long as I get to eat.
I always say use whatever is locally available, where I am there is alot of pecan, so I use pecan a lot. Great smell and a light flavor. North Carolina it was hickory, Texas mesquite. Wood should be an extension of your enviroment.
One of the great unrealized benifits of Todd's pellet amps is the easy acess to all wood flavors. There are still woods I have not tryed, and I am still enjoying learning where they best fit. But its part of the enjoyment of smoking. The woods, sauces, rubs, the preps, etc etc etc........