It's a bit like asking what oil to use. A bit of a mine field.
I've given many a go. Auto glym was my favourite but that was 10 years ago and products have changed a lot in recent years.
At the moment my cupboard contains :
Poor boys for general waxing and sealing
Chemical guy's for general waxing and sealing but also product for tyres, trim and rubber hoses
Prima sealing wax
Mezerna for dual action cutting polishing
Meguiars detailer and clay bars
Plus a few other bits......you know the kinda stuff you get given by family for Christmas and yes that includes auto glym. Now only used for tarspot removal and cleaning the conservatory.
My advice would be to check out
www.cleanyourcar.co.uk and read some of the product reviews.