These are products I will never be without:
Blacklight. I think it's one of the best car care products available. Does so many things well... Can be used as an AIO, or a glaze or a sealant or a foundation under any carnuba wax or sealant. Applied with a DA or by hand. Incredibly easy to use.
V7 spray sealant. Incredible over Blacklight, great on wheels, door jams, glass, plastic.
Citrus wash daily. Best bang for the buck wash. Can be used to strip or to maintain. Great in foam guns too. One gallon works out to 17 cents per wash! For volume or mobile businesses its hard to beat.
G6 hyper dressing for tires, vinyl, and plastic. I love the look on tires. Very easy and dries almost instantly. One bottle lasts a long long time.
Glossworkz glaze. Amazing filler, great gloss enhancer and looks great under Blacklight. It's like EZ Creme on steroids.
Monster blue MF towels. I haven't found anything that lasts as long or is as flexible in terms of possible uses.