I agree: Apple, Pecan or Hickory are great wood for smoke. I really like Cherry wood, but that's cuz I get it fo' free (but it is good wood for smoking)
mesquite and a lot of water (and low/slow) are about the only things I'd tell you to avoid. I generally can't oversmoke anything anymore, but to me, those would be (probably recoverable) mistakes.
Most of the time I use a mix of Apple and Pecan. Most of the time I use just a little for a light smoke, but every once in a while I'll add some Mesquite to kick up the smoke a notch or two.
I really love apple. I use it on chicken and pork. The smell of it smoking to me is so much more appealing than hickory. I like cherry too and use it on beef.