First, I just want to say that I'm not a hair stylist and I don't know much about the scientific make up of hair. My information is just based on the experience I have had with my hair/hair products.
My hair is dark brown, nearly black and is very thick and around my shoulder blades in length. Years ago I would buy the cheapest product I could find (White Rain, VO5, Suave). During those years my hair was always dry and brittle with split ends and had lots of static, especially in winter but even in summer too just after a wash. About 6" up from the ends of my hair had turned such a light brown that people were asking me if I had bleached or highlighted. This went on for a period of approximately 10 years.
Then I started using all Pantene products. My hair improved slightly. It didn't have as much static and it was less dry. My hair was still really drawn out in color though since I am outdoors and in the sun a lot. I did seem to get a lot of build up on my hair from the Pantene and every so often used either the Pantene clarifying shampoo or I would use about 1 tablespoon of baking soda before washing.
(With the baking soda you just make a paste with it and water and gently rub it into your hair for a minute or so. Just be careful and don't get any in your eyes. Then rinse well and shampoo as normal. It works excellent.) It is my opinion that Pantene is the best over the counter product available, at least for me and my hair. I used Pantene exclusively for about 5 years.
Then, about 8 years ago I switched to salon brands. I have tried many including Paul Mitchell, Biolage, ISO, Redken, and many others. For about 2 years I have been using Big Sexy Hair shampoo and conditioner. I think about all of the salon brands are equal and that it is just a matter of finding one you like best as far as scent, texture, foaming ability, etc... My hair started improving as soon as I started using salon brands. I hardly ever have any buildup and if I do it's mainly from using hairspray and then being in the sun all day and the hairspray sort of baking on my hair. The color is not drawn out like before and I don't have broke off, split end hair like I did before. Maybe it is because my hair doesn't have a build up and the brush/comb glides through more easily??? I really don't know.
Anyhow, I get lots of compliments on my hair now. Complete strangers often comment that my hair is shiney or pretty or that it looks healthy or something. And, my Mom and I both have decided that using salon brands isn't really any more expensive than using Pantene or other over the counter brands. With the salon brands it doesn't take near the product as it does with the over the counter brands. In other words, it only takes about a third of the salon brand to do the same job as the over the counter brand, so a bottle of the salon lasts us as long as three bottles of the over the counter. Also, I don't buy a bunch of treatments to help my damaged hair like I used to so I'd say I spend about the same for haircare now as I used to. If I do spend a little more it is definitely worth it to me. I usually buy the Big Sexy Hair products at the salon inside Wal-Mart or from right here on eBay if the seller has good feedback. It is not that expensive.
Some other tips that work for me are:
* The healthier I am inside from diet and exercise is the healthier my hair appears.
* Being very gentle when brushing/combing/styling hair is very important. Keeping hair well conditioned will help keep it from being broken off when styling.
* Dry hair as much as possible with a towel (blot or squeeze, do not rub) before blow drying.
* Do not use overly hot water for washing and rinse hair extremely well after shampoo and before using conditioner.
* Do not overheat hair/scalp with blow dryers and curling irons and such.
I know everyone and their hair is different and this is only my personal opinion and what works for me.