While I've never been a fan of the exclamation point, I don't have the same vitriol for it that Twain, or even an insane creative director of mine, had. I had worked on a print ad for Panasonic many years ago and the headline used an exclamation point. It was cheesy but intentionally so. Anyway, I got called on the carpet by this guy. I thought it was a joke but apparently, he had spent years trying to get this client to get away from exclamation points and I undid all of his hard work. Ahh, advertising.
My problem with the exclamation point is the false enthusiasm it evokes. I'm not a cheery guy. I hate the cheeriness that it might force from the person reading anything I've written. My hope is that if I do use it, it'll be obvious to everyone that I'm being sarcastic or intentionally goofy. So I did an unofficial† survey: I asked people what punctuation mark I remind them of. (†=completely made up)