I agree totally on Conroy and Hammill. When I measure TDK against other Batman films, I also measure it against Mask of the Phantasm, heh.
TDK is FAR, FAR, FAR from perfect, but it is so much closer than the other serious live-action Batman films that it's no contest as far as which is the best of those.
I don't know much about the English voice actors for Cowboy Bebop... I only watch subtitled foreign-language stuff if I have the opportunity.
I didn't think Cowboy Bebop was close to Batman: TAS in terms of overall quality (especially given the last two episodes of Bebop where they realized that they had this big story arc planned all along and had done zero with it up until then). That said, I think it's something that can grow into a franchise that delivers something better than the anime. A movie may well fit into that strategy, but Keanu Reeves turns it into instant fail. Spike is a charismatic, funny character who is actually skilled in martial arts, and Keanu can't even go 1-for-3 as far as that goes. It's ridiculous, but of the big-name actors out there I know of, I'd say Ben Stiller is as good as anyone else for the role. If you want a "perfect" (true-to-form) Spike, I can't think of anyone appropriate so an unknown would have to be cast.
Oh well, at least we've heard nothing about the EVA remake as of late. A good thing if you ask me. Cowboy Bebop, even if you don't want it "tarnished," can be transitioned to live-action far more easily than Evangelion.