I think a lot of it depends on what kind of rub / marinade / sauce you're planning on using. I've recently done a couple batches of chicken thighs that had a pretty spicy (cayenne) rub on them - and I used Hickory both times. They came out great.
I've used apple, cherry, and pecan (sometimes in combination) and I've had good results. One thing I've noticed is that cherry wood seems to give your meat a darker color than the others. But the taste is still good. Something to keep in mind. Good luck.
Apple, cherry, peach, or any fruit wood, but pecan and oak is great too, along with sassafrass.... even hickory as long as not too much and not one of the super strong species. It's (almost) ALL good!
Per the above, cherry or apple work well depending on the flavour you're going for. Sugar maple is nice and light. Hickory brings a lot of flavour if that's what you want. Really, I'd only avoid mesquite. I'm also not an oak fan but that's just me.