If you don't have plans to see this movie, you can check the spoilers here and then come back.
Coming out Pain & Gain, myself and the other guys I saw it with more or less agreed on two things: we liked it and we'd have a lot of trouble describing it to anybody who hadn't seen it. The short version would be to say it's a movie about fitness trainer Daniel Lugo getting a crew together to hold hostage and extort a rich client and what happens when the plan goes right and then wrong, but to do so would be a disservice to everything going on in this film. At various times it's a screwball comedy, a heist movie, a very dark comedy, and a thriller, with all four of those and several more genres frequently crashing or bleeding into one another pretty seamlessly. I'd say it has a very similar chaotic energy to To Die For (the Nicole Kidman one) or even Fight Club. Mark Wahlberg plays Lugo in a way that immediately called up for me Christian Bale's turn as Patrick Bateman in American Psycho; they're very different characters, but both characters call upon an ultra intensity and rapid fire delivery to bring earnestness to the ridiculous. Wahlberg is par for the course brilliant from his crazy voice overs to some really funny physical comedy. Great as Wahlberg is, Dwayne "The Rock" Johnson matches and perhaps surpasses him as Paul Doyle, a born again ex-con and former cocaine addict who gets drawn into Lugo's plan. Johnson basically plays an array of characters over the course of the story: the repentant man of peace, the strung out crackhead, the intense criminal and various combinations therein and he's fantastic as all of them with his commanding presence, unmatched charisma, and brilliant comic timing. This should be the movie that propels Johnson past being a kids movie headliner or part of an action ensemble into a full-on leading man. Christopher Markus and Stephen McFeely wrote the screenplay, based on a book by Pete Collins--oh, and this is all based on a true story, by the way--and their script is top notch; this movie is eminently quotable both from a "that was really funny" stance and a "that was really deep" one. Michael Bay directs, and even though there is at least one major explosion--and a lot of uncomfortably violent moments that pop up when you least expect them but do feel earned--he does a great job, using slo-mo cuts for great comedy, employing voice overs to really convey the story, and being smart with his effects. Beyond Wahlberg and Johnson, Tony Shalhoub is perfect as the sleazy jerk they kidnap and Anthony Mackie holds his own as best he can as the third member of the team (it's hard not to get a little lost in the shuffle considering his co-stars). The movie is somewhat bloated at 129 minutes; it could lose 40 of those and not suffer. There's also a distinct cut-off point where it feels like one act ends and another incongruous one churns up when Ed Harris' detective character--fine performance, but the character himself feels imported from another movie--enters and the pace slows down. There are certainly things Pain & Gain could have done better, but it already did enough right that I'm still thinking about it a day later and writing more than I usually would and still feeling like I barely scratched the surface.