Poorboys Nattys Paste Wax is the best for the £ by far.
If you want out and out shine, Chemical Guys Butter Wet Wax, but it will last only a few weeks. Whereas Nattys lasts months.
www.obsessivecardetailing.co.uk
I agree on the Autoglym window stuff, I use Quick Detailer on windows - its good for all panels, especially while drying the car after a wash. The specific stuff I use the the Meguire Nxt Generation Speed Detailer.
Chris