No doubt IS binoculars are the only way to go since you can increase the magnification significantly without any annoying hand-shake effect.
I recently picked up the 12x36 IS II, mostly for sporting events, and I was blown away by the bright and sharp view these produce and I've owned and used lots of binoculars in my days. Focus is smooth and easy even while depressing the IS button.
I could not find any Canon IS binoculars in my area to play with before purchase so I had my wife drop into B&H when she was in NYC. She picked the 12x36 IS II. So if you had to make a blind purchase, I don't think you could got wrong with these unless you need water resistant then you might look at the Ls.