I decided to do a fan cast for the Excalibur team. I've stuck with purely British actors for this one.
Brian Braddock/Captain Britain - Jamie Bamber. Amazing actor, as evidenced on Battlestar Galactica, and more recently in Law and Order: UK, relatively youthful, handsome and more than has the build for a superhero (just look him up on Google and you'll see more tha your fair share of him in nothing but a towel), and looks just like Brian in the face too.
Merlyn - Christopher Lee. He's already played a badass wizard on Lord of the Rings. I'm open to other suggestions though.
Roma - Natalie Dormer. Gorgeous and talented? What more is there to ask for?
Elisabeth "Betsy" Braddock/Psylocke - Lena Headey. Since Psylocke is Brian's twin sister, it makes sense to cast her, right? And Headey is not only good looking, but she great at being tough.
Jamie Braddock - James Purefoy. I'll admit that I haven't seen much of Purefoy's stuff other than a couple episodes of Rome, but he was great in them, and would be pretty funny as Brian Braddock's crazy big brother. And Purefoy, Bamber and Heady actually do look like they could be siblings.
Meggan - Rosamund Pike. She's been making her name in several movies, and she's just perfect. She's got a down-to-earth quality to her that fits in perfectly with Meggan's elemental empathy.
Pete Wisdom - John Barrowman. Just watch him in Torchwood, visualize him with longer hair, a beard and an eyepatch. I'm open to other suggestion with the caracter too.