I don't know the "BEST". There is bound to be disagreement, depending upon such things as ease of use, effectiveness, environmental impact, price/benefit ratio, etc etc, etc...
Your best bet is to WAX the wheels once they ARE clean, to help make them easier to clean. There are waxes specifically for wheels available, but whether they are better than a paint sealer, or carnuba wax is also up for debate.....
All that said, I waxed my aftermarket wheels with paste wax before I put them on the car and now use Griot's Wheel Cleaner.
. I use their four finger lambs wool mitt and long reach
NFI, just satisfied.
I do my best to wash the car once a week, by hand, and go no more than two weeks between wheel cleanings.