The Keratin was definitely not for me either - I can tolerate some protein, but shea butter makes my hair do bizarre things! The Argan is much better, and I haven't had any buildup issues, but then I alternate my products pretty frequently.
The one I like the best is the new Australian "Sun and Surf" line. I get less frizz and better curls, and it has the same intriguing smell as the other formulas (oh.hi.its.steph describes it as reminiscent of Play-Doh, which is spot on).
YTC is also quite good, and I'm considering the Cucumbers poo and condish as well, based on the glowing feedback on the board (I'm such a lemming - hangs head in shame).
After a major spending spree when I first went CG, my primary objective now is to find reasonably priced, locally available products that give me results I can live with.