Criminal Minds is one of the hottest crime shows on the block, and not without reason. At times, the acting can be quite excellent and the plots suspenseful. But other times it can fall short. It has some well-developed characters like Hotch and Reid, and then some blatant stereotypes/unoriginal characters like Morgan and Garcia. There's some quality acting (Gibson, Gubler, Mantegna, Patinkin) and then some mediocre to stiff performances (Moore, Cook, Brewster, Vangsness). Sometimes the episodes can really make you think; other times the point of a certain episode is so unbelievably clunky and riddled with cliches that you want to laugh - I'm thinking of the Tobias Henkel arc here.
Overall, I'd have to say major points for cast chemistry: you really wanna watch this for the team members' relationships between each other, even more than the thrill of trying to figure out whodunit or why they did it. Points off for the occasionally ridiculous amounts of gorn, poorly written storylines, and a good dose of awkward acting.