I've used Redken for years, but these days I'm into Phytologie, a French line. My sister has been a cosmetologist since 1974 or 1975, so I get stuff at half-price.
Right now, I'm using Phytologie's Phytocitrus, because my hair is relaxed AND colored. I also use Phytocypres, because I have a very sensitive scalp that needs exfoliation.
Good topic.