When I got my first car I was bought an Autoglym gift pack which I used but I found the polish to leave a powdery residue.
Soon changed to Meguiars and have never strayed since. Use the gold class wash and then leather off (or a spin on the dual carriageway). If I want it to look mint then I use the 3 step process (takes an hour or two) but normally I just give it a layer of Step 3 Wax.
A friend of mine uses Zymol which is very expensive and doesnt produce any better results in my opinion.
Here is a pic of my old 1.8GLS Vectra:
