I Don't Believe in Fairy Tales by TatyanaOracle (HD available):
This is a Natasha/Clint vid. I like the choice of music -- "I don't believe in fairy tales but I believe in you and me" is a good motto for them. I also like how the vidder made a virtue of necessity in dealing with the imbalance of clips available between Natasha and Clint: Natasha is almost always in motion while Clint is mostly stationary which works with him as a sniper and as the one in need of rescue.
Settle Down by almostgaby -- the vid seems to have been removed from youtube but you can still download it from mediafire
The vid is very technically well done with a great choice of clips. (At least to my uneducated eye.) The great part is watching Natasha "trying to get a hold on this" as people keep doing stupid things all around her. I hadn't realized how many great "you idiot" facial expressions she made until I watched this vid.
So What by kaydeefalls
The last isn't really strictly a Natasha vid. The vidder describes it as "A tribute to the kickass ladies of the Avengers cinematic universe" and that's just what it is. The song is a lot of fun and the clips are great -- not just the expected Natasha ones but others like Peggy Carter punching a GI and shooting Steve. (I'd forgotten how much I liked Peggy and Steve.)