For lean trimmed brisket, I like cherry/pecan/hickory at a ratio of approx 40/40/20. I like cherry/pecan/mesquite at around 40/30/30 for most other cuts of beef including 7-bone whole beef rib (prime rib), rib eye steaks, top/bottom round roasts, chuck roasts of all sub-types, and various other cuts of steaks.
Pork is a bit different for my preferences, with apple being my main smoke most of the time (not always), usually followed by pecan, and sometimes a touch of hickory. For fresh shoulder cuts including steaks, 40/30/30 to 40/40/20 is good. For loins and chops I typically go a bit milder on the hickory, and mostly apple, maybe 60/30/10. I have also used apple, pecan, cherry and hickory on pork shoulder cuts and it always comes through nicely at around 40/20/20/20
Chicken is still good with some hickory as long as you keep it in the background...just enough to give it a little bite, but mostly the sweeter apple, and a little pecan if you like. Apple and cherry is nice for birds, too...I just use less cherry than apple.
Cherry is a heavier fruit wood smoke, but it does lend a little sweetness in the background...being heavier, it seems to pair well with most beef and shoulder pork cuts.
Mesquite is one if the woods I tend to use with more caution, as it can become very heavy/earthy. Hickory is bit more forgiving on pork shoulder and beef, but is still one I use with care. All the rest I mentioned are pretty forgiving, so if I use hickory or mesquite along with a few others, I'm pretty safe on it being quite palatable when the smoke clears at the end of the day.
Maple is a relatively new one for me, in pellet form, blended...Todd's Pitmaster's Choice...the maple really adds a great depth to the sweetness of the flavor and aromas to go along with the hickory and cherry...I've had some great eating meats come from this blend...cold smoked cheese, too, btw.
I do enjoy that pungent aroma of pecan, but if there's something else in there with it, it really seems to wake up the senses. I've been blending duos and trios for a few years...it's fun to play with the variables (within reasonable boundaries, of course) and taste and smell the results.
Have fun with your smoke!
Eric