If you want to stick to one product line, I would recommend Optimum as you can do the most with the least cost, in my opinion. The products are tried and true, as well as cost effective. Realistically, you need Opt. No Rinse Wash and Shine (rinseless washes, clay lube, quick detailer, glass) Opt. Car Wax (LSP), Opti-Bond (tire dressing), Opti-Clean (waterless wash, interior, wheels, tires, etc.) and maybe Optimum Car Wash if you want to do a traditional wash.
That said, there are winners in the Chemical Guys, Poor Boys, Duragloss, CarPro, etc. product lines.