I always thought SF TV Show Alien/Monster regular Brian Thompson would've made a good Dredd - has an incredible jaw and a kind of wry edge to his monster acting. Certainly if they went for a TV Show and kept Dredd's Helmet on...

Cheers

Edit - here's his IMDB photo - you might recognise him (Was the Alien Bounty Hunter Assassin shapeshifter in the Xfiles)