What is the best type of wood to use to smoke a turkey?

I would use the pecan. Mesquite will give a very distinctive flavor. If you like that then Mesquite would be a good choice. Personally, I am not a mesquite fan.

Pecan is the best, although a lighter wood such as apple or cherry would be preferable in the future. You might be able to get away with oak and hickory, but mesquite will definitely be overwhelming. It is actually possible to smoke a food item with a wood whose flavor is too aggressive. Oak, hickory, and definitely mesquite fall into these categories, as they are the heartiest and most aggressively flavored woods available.

For several years we've done a brined Thanksgiving turkey on the grill, smoking it with hickory chips that have soaked in water for about 30 minutes. The results are always outstanding.

We've also gotten fabulous results using smoking chips made from old wooden (oak) wine casks (usually available at specialty barbecue retailers). For poultry, chardonnay chips are our favorite.

Applewood usually works very well with poultry. It's a nicve light flavor. Heavy ones like mesquite might be to overpowering...they are good for red meat, in my opinion.

I tend to do more hickory for my smoking.

Depends what flavoring you are looking for...