I have to say, I generally prefer Pizza Hut, but here in Iceland, a large three cheese pizza is going to cost over thirty pounds, so it's well beyond my price range. Dominos isn't too bad, nothing to write home about, but it does the job and is as cheap or dear as any pizza place in Reykjavík. No vouchers out here either.
Back in the UK, Pizza Hut all the way, baby.