For all Chuck fans out there I sincerely recommend That Which is Greater by Frea O'Scanlin. This is an alternate universe where Chuck has a four-year-old daughter at the beginning of the series and it changes pretty much everything.
This is a great read: the writing style is great and the author does a great job of mimicking the speach patterns of the original characters. I swear, I can't tell the dialogues from those written by script writers of the original series.
It's primarily a romantic/introspective story though, so don't expect James Bond stuff here.
Also, other stuff she's written is also good. I've read her Felicity/Oliver Arrow fanfic and it's just the right blend between comedy, romance and common sense.