I bought 'Redken Real Control Intense Renewal' hair mask awhile ago and I have to say, that I really like it. I find that it really helps to moisturize, condition and repair my hair from the coloring that I do to it and also the general dryness that it tends to get over time.
Pros - Moisturizing, smells wonderful (it has that salon product smell, light and clean), creamy, covers and conditions hair well, product lasts a long time even if with regular use, attractive packaging.
Even though this product is somewhat expensive (depending on where you get it from), I think it's an investment. You aren't going to use it everytime you wash your hair and a 8.5 oz. tub with last you a long time.
Cons - Not available everywhere, might be too heavy and moisturizing for very fine hair. I think this hair mask would be best for thick, damaged or frizzy hair. If you do have very fine hair and want to use this hair mask, I would only use a little bit and I would really concentrate it on the ends.
Do you have a favorite hair mask that you like to use? What is it and why? I would love some recommendations!