I've tried all manner of different manufacturers (for all car cleaning products, not just polish) but every time I keep coming back to Autoglym stuff.
Its not the easiest stuff to work with the car needs to 110% dry, and you can't skimp on effort - but I've never achieved the same results with another manufacturers stuff - its terrific.
Smell is first class too! Which is important if you're sniffing it all day!