BOSS is amazing for Mingus (bright blood bay) but doesn't give such visible results on my other horses...not to say that it doesn't benefit them healthwise...
Shampoo: Citrishine (which I use for my own hair) works great on everyone, making their hair soft and shiny.
Conditioning: I've yet to find anything that beats Cowboy Magic. Again, it gives the most visible results on Mingus' glossy black mane and tail, but for everyone it is great for keeping mane and tail tangle-free and preventing breakage.
Sadly, considering I love long, thick manes and tails, Mingus just doesn't grow that much of either. I tried supplementing his great diet (LMF, BOSS, beetpulp, excellent quality orchard grass hay) with biotin, yet all it did was make his body coat grow longer, which I didn't want!
Cross my fingers, but so far Scarlet's white spots and tail seem to clean up shiny white, not yellowish. We'll see if this was a fluke or darned good luck for me. She loves to roll in the mud, so right now it's hard to tell she's even pinto!
I love to trawl through the cosmetic section at Fred Meyer and WalMart, checking out inexpensive hair products. I LOVE Pink (mink oil) spray...LOVE Shine (a pommade for African American hair), but you must rinse it out immediately, as it dries the skin and hair.
Just For Men is great for touching up sun fade, but I'd rather do a horsey comb-over...