I use either Aveda Deep Penetrating Hair Revitalizer or TIGI Bed Head Chocolate Head depending on when and how dry/protein needy my hair is feeling or acting.
I usually use the TIGI about 2 or 3 times a year (I've only used it once since I first jumped onto the product in April, it works that well, mostly because it has the strongest protein, keratin, in it).
The Aveda is really for those inbetween times. Hope that makes sense.