For chicken,I like Webers Kickin' Chicken.
For ribs,either Stubbs chile-lime or Weber's classic BBQ.
For butts,I've used the McCormick bbq rub. Pammi didn't like it,so I won't use it anymore. I do like Bad Byron's Butt Rub and I did a butt earlier this year with the Weber's classic bbq.
For brisket,Pammi will only let me use Steven raichlen's coffe rub. It's pretty yummy!
I've tried making my own rubs before and Pammi hasn't cared for them,so that's why I use premade stuff.
I typically make my own but when I use something commercially I order the rubs from here:
http://www.texasbbqrub.com/shopping.html
Bill always fills and ships orders quick!!