21
A generous person would regard it as a positive trait of mine—forgiveness, the ability to grant the benefit of the doubt—that I can tell everyone who will listen that a movie looks like it'll suck harder than a $10 whore but then I'll go tosee it anyway. As it turns out, 21 sucked a lot less than I expected. It's based on the book, Bringing Down the House by Ben Mezrich, which I read and really quite enjoyed some years ago.
The movie diverges significantly from the book, which itself is a true(ish) story, but this turns out to its advantage in my view. The movie introduces an antagonist in the form of Laurence Fishbourne's Vegas security consultant, and wedges in the mandatory love interest too, neither of which I remember from the book. These changes ultimately make the story a better fit for the movie medium, though they're a little more on the formulaic side than any of us would have wanted.
In fact the whole movies looks like it came off the end of a production line, with fewer surprises than a transparent Kinder egg, but if it doesn't stand out as fantastic it also doesn't stand out as terrible. The gambling and maths angle appealed to me, and made it that much more enjoyable. In the end I wouldn't be confident in recommending it to someone who didn't share those interests.
Maybe sit it out and go play the slots instead.