so far only used 2 brands which is
1. meguiar's tech wax and polish
2. turtlewax (with silver shade chipstick)
3. soft99 (metallica silver edition)
personally i think they're superb so i've never bothered 2 use any others. my only complaint is that they're on the expensive side but i suppose it's quite worth it since i notice the shine is long lasting and the shine is SERIOUSLY shining & gleaming. the turtlewax works WONDERS for scratches (even VERY deep ones), chips and general color restoration (especially around areas like the rear bumper surrounding the muffler which always seems 2 go terribly black from the ekzos fumes and flames)...
i recommend trying out both of the above mentioned which can b purchased pretty much anywhere like eneos, ace hardware etc etc. turtlewax also offers different shades of colours depending on what colour ur ride's paint is :)
as for da worst i've never used any other waxes/polishes b4 'n' i'm happy wit d ones i'm using now. so can't really say la. but have heard complaints from different ppl about different waxes. quite subjective really.