I've found that the best type of shampoo and conditioner for curly hair is not the ones "especially" made for curly hair but the ones that specialize in frizz control, shine and hydration. Curly hair splits a lot more than any other hair type so hydration is super important. Also, no one wants frizzy hair but frizz and curls go hand by hand so frizz control is a major plus in shampoo and conditioner. Warning: STAY AWAY FROM ANYTHING VOLUMIZING!! Volume shampoo and conditioner tend to create curly hair afros.
All Time Favorite: Garnier Fructis Sleek and Shine
This stuff works magic! You can actually feel your hair get smoother as you apply it and it smells so nice. It has Argan oil and apricots in it that control the frizz. Side Note: Anything Argan oil is awesome for curly hair! The price is not bad either and it can be found at just about any drug store. I got mine at Wal Mart for $6.97 each and it has lasted me about a month now. I'm expecting at least another 2 weeks out of them. It's also awesome in the summer because it resists humidity. Basically you can not go wrong with this combo! I would recommend this even for people who don't have curly hair. they are just overall amazing.
Try them out and let me know what you think!