Personally, back in the early days, I chose quality over cost... Demon.
And they were excellent, until the owners cashed in and sold the company, in what proved a spiral of decline, 'Thus', Scottish Power, and eventually... bottom of the barrel... Now Vodafone.
When it all got too much, following some hilarious (and depressing) 'support' episodes I decided to switch and again I chose quality, went for Zen. After Demon's collapse, they were a breath of fresh air.
And so they remain, no regrets at all with Zen.