BG additives are the only ones i've found to actually work.
The offerings from Archoil are relatively new and seem to work well but I've not done any extensive testing with them yet. Preliminary findings are good though.
AR6900-D MAX
BG244
I would avoid Cetane boosters, carbon and injector cleaners, they usually cost far more than it would to just fuel up with a decent fuel with these additives already in!
Shell, BP Esso Fuels etc... all contains cleaners, injector cleaners, decarbonizers etc.
You can actually get a lot of these items at no extra costs on our Amazon link and the sales will earn us a small commission which helps to offset our running costs.