One that I can recommend is "Scott Pilgrim vs the World"
Most Helpful Guy
Why under what 90 minutes that's lame
I don't know how long it is but Kick-Ass is pretty great.
Superbad is funny as fuck and pretty lighthearted.
The Kings of Summer is entertaining but it could make you think possibly.
Most Helpful Girl
Honestly I'd suggest Stardust, but I don't know if you'd like it. I think it's funny, and has a happy, nice message, but it might be a little too happy for if you're about to sleep. I don't know!