Highly underrated as an actor, he tends to get mainly comic roles, but I have seen him do an excellent villain. The man can be dramatic, he can be downright frightening, and I'd really like to see him get to stretch his acting legs by playing ... a less friendly version of Picard, essentially.
I mean, we never got to see Picard being a super-hardass, but nearly everyone who served under him felt he was a man you did not
want to have be angry with you.
Plus, I think we've seen enough tall, broad-shouldered captains. Time for a short guy to be awesome.