First off, a lot of people are getting the thread wrong. It's a hypothetical scenario, it's not a "Replace James LaBrie with another singer right now" sort of thread (although the title makes it look like that
). The point is just to think who would you like to see in DT in case - God forbid - James left the band.
I can't really think of someone at the moment. Most of the other singers I like just have a whole different feel and texture to their voice and I'm not able to picture any of them in Dream Theater. It's not just a matter of hitting the right notes, but of feeling like the singer actually fits the music. Perhaps I'm too used to JLB's voice in DT songs, which is only natural after 11 albums and over 20 years in the band, but I just can't. It's similar to when DragonForce's (sorry if anyone hates the band in here) singer left: I couldn't imagine anyone replacing him. They got a much better (in my opinion) singer, and his voice is way different from the former singer's, but he actually fits the music just right.