Dish aerial?

May seem silly question but.

Dish or conventional digital roof aerial which is best to use on my caravan to obtain best reception and using digi top box?. I recon a dish ' er in doors' the wife, argues against dish [cost] and it nearly came to blows in our c/van because with conventional aerial had both crap picture and sound. I think this would have be a lot better with a dish aerial. UK recent break in Devon with s..t picture and sound.

Bob
October 2009