In the realm of badassery, I'm a big fan of skills that you "pop" in general. I'm not talking about the kind of abilities you stuff into a macro or pump through a reminder addon. How plebeian. You don't even use the word "pop" to refer to those abilities; you just stick 'em in the rotation and let them mop up. (/yawn) Being badass happens with those abilities you don't pop as soon as they're up because you're waiting for the perfect moment -- and when it comes, you feel like a hero. Yeah, like Heroism. (Or Bloodlust. Because that just sounds more badass.) Even slightly less-than-heroic cooldowns can make you feel like you've grabbed hold of a passing star. I'm addicted to that grating Inner Focus sound effect because I know it heralds an angelic bestowal of life-saving heals. See that crit? I saved your butt right there. You're welcome.
In the scope of cool cooldowns, Inner Focus is pretty tame. But still, you know? But still. So what cooldown makes you feel like a real badass?