It really comes down to what you like. However, I tend to use the sweeter woods on pork and chicken. (Peach, cherry, maple, hickory). I use mesquite on beef since it has a stronger flavor. Mixing woods is also a good solution. 60% peach and 40% mesquite is great on chicken. Mixing woods is easy for me since I'm a pellet smoker. Hickory has that traditional BBQ flavor.