The guy who plays Draco Malfoy is called Tom Felton. I think he plays the role perfectly! My favourite actor from the Harry Potter crew.
I heard that Jamie Bell, who was already mentioned here, also applied for the role. He's a great actor i think, maybe Radcliffe looks more like Harry Potter, but you can dress up any boy like Harry Potter. There were thousanRAB who wanted the role. i think Radcliffe acts okay.
I have a question: Are we actually talking about young actors or child actors?
I interpreted the topic as about acting talents who could become a big star, and so they could be aged until 25 or something.
Some people mentioned Jake Gyllenhaal, and I can only agree to that. The same with Haley J. Osment - what's he doing at the moment? I didn't hear much from him in the last time. I read that he did some synchronising.
To suggest somebody less known: I was amazed by Jordan Brower on the (little trashy) movie "Speedway Junky".
Some days ago I watched Bertolucci's "The Dreamers" and the young actress in the female leading role, her name is Eva Green, made a memorable performance. I usually forget quickly who did a good job if I don't know the actor, guess I remember her because it's not too long ago that I watched the movie.