Check out BatDad on Youtube, who corrects his kids using the mask and a Bale-style voice. 
I pretty much agree; however, having heard clips of Mr. Conroy on Youtube, I’ll admit that I’m impressed.
To those who have never watched the cartoon, at the very least seek out the movie Batman: Mask of the Phantasm. It is the best movie adaptation of Batman ever (including the Nolan movies) and does a better Batman Begins story than Batman Begins did.
Conroy. I can’t fathom any other answer.
Adam West. Too many of the other Batmans sound like chain smokers.
Voice acting is real acting.
My city police department is replacing black and white cruisers with all black Tahoes with very very dark grey lettering. I can’t help but hear Lego Batman every time I see one 
I watched Batman: The Animated Series from the first episode, and I say Keaton. What’s-his-name from the last few movies had the worst one, though. Christian Bale.
No, they want to keep these movies grounded in reality. The device on his voice box will translate everything he says into ultrasonic squeaks, like a real bat.
I’m rather partial to whoever is doing Batman in Batman in Classic Movie Scenes. Especially the Home Alone bit.
Or CollegeHumor’s Batman Chooses His Voice.
ETA: Contains some NSFW language.
You’re only saying that because Clooney didn’t actually have a Batman voice; he just delivered the same Clooney voice, and Leno head-bob, in and out of costume.
Just like Adam West - which makes sense, seeing as Clooney was essentially in a big-budget version of the 1960s TV show
Pretty much. And Clooney’s non-differentiaton was less distracting than Bale’s version, which, um, insisted upon itself.
I remember an episode where he was taking a phone call as Bruce Wayne from (IIRC) Lucius Fox while in the Batsuit. The dissonance really highlighted the distinction.
The gravelly old-Bruce voice he used in Batman Beyond was also nicely distinct from both of the above.
True enough, and I didn’t mean to denigrate Kevin Conroy’s performance with my agreement with Blank Slate, above, though I do think that it’s not really fair to compare a full-on live actor’s performance with a voice actor’s.
A live actor gets the chance to interject body language, facial expression, timing, etc., that a voice actor often does not.
Michael Keaton’s Batman is still my favorite, and I also think Val Kilmer’s turn as The Bat is underrated (Clooney, IMO, “phoned it in,” and Bale’s voice was just too distracting for me; I kept thinking “There Can Be Only One!”
Which, if you think about it, just emphasizes how awesome Kevin Conroy’s Batman is; he’s doing all the work with just his voice.
Got to be Adam West.
There is no other Batman.
Conroy. Now and forever.
That’s a neat video, and there are some decent voices in there…except for Ron Perleman, who sounds like Ron Perleman. It really does not work.