If you don't have plans to see this movie, you can check the spoilers here and then come back.
This was a passably entertaining movie, but not a great one; by that I mean I enjoyed it, there were some legitimately funny bits, it moved along nicely and so on, but if you want to break it down, the plot was pretty slapdash, the transitions were awkward and there were huge logic holes even for basically a teen romantic comedy; however, none of this mattered. There are some films that are above all else a showcase for a single actor, which is what this was for Emma Stone, and she was spectacular, elevating the movie from something that would have been forgettable with another lead into the one we'll probably all look back on as her big star turn. I can't remember the last time I saw a legitimate turn the corner "whoa, he/she's going to be huge" performance like this, but it really bowled me over; Stone was endearing and fun in Superbad and Zombieland, but she carried the show here as the headliner and seemed to do it with ease. She seemed incredible relaxed with whatever was asked of her and able to seamlessly toss off every piece of dialogue or physical gag into something that made you laugh out loud; she really seemed totally at ease, like this wasn't even work for her, and that made you feel similarly relaxed, allowing you to just kick back and have fun with it. Stone is an incredibly endearing star who did a lot with a decent amount here, so I can't wait to see what she does with headier material. To be fair, she also had a pretty great supporting cast, particularly Stanley Tucci and Patricia Clarkson as her laidback parents, who legit seemed to be having the time of their lives and just goofing around as they stole every scene they were in, Stone's "let's just have fun" enthusiasm" spreading to these veteran actors; Thomas Hayden Church was also funny as the dryly witty favorite teacher and my boy Penn Badgley delivered as the nice guy who rides in on the white horse (really the only role he seems able to play, but hey, he does it well). Ultimately though, this was Emma Stone's show, and she rocked the house.