I saw Contagion couple weeks back and thought it was mediocre. Felt like it was rushed and there were alot of plot holes and characters with half decent screen time just disappearing. Ending was great however.
Then saw Chronicle and thought that was amazing. From a realistic standpoint, they hit it head-on. If anything like this happened to real teens, i expect nothing less from what happened in the film. Alot of friends complained that the build-up was slow, but i enjoyed the build-up and coming together the guys had for the climax.
Lastly saw The Vow with a guy friend. It's nothing like the Ads in terms of how it's played back. It's flashback-ish but it only does it to explain important plot points for how Tatum attempts to win her back.