For those of you who have not watched Chuck before, I would recommend that you check out Season 1. Although Season 2 is superior in my opinion, Season 1 really lays down all the groundwork for what is to come.
For those of you who have see Season 1, you will not be disappointed by what the new season has to offer. In S1, Chuck was mainly the passive observer, the guy who flashed on things, and often made situations worse than before. However, at times he was given opportunity to save the day, in something I like to call a 'Chuck Moment'. Season 1 had a few of them (setting off the fireworks to distract the guards to save Sarah and Casey would be one) but Season 2 is full of them - and better off for it. Now don't get me wrong, Chuck can still be blundering and innapropriate, but in the new season, he always gets the opportunity to be the hero. The first episode has a particularly good example of this.
The season starts off very strong, following on with the storyline that involves the governement trying to make a new intersect (and invariably the team have to go on missions to help furthur that cause). In fact, the majority of the season is brilliant television, apart from a few select episodes that are merely good, dotted around the season. The season has a much more coherent storyline, with a smallish story arc near the start, and a solid story arc that takes off around episode 13.
The character's pasts are delved into alot more in this season, with a great appearance from Sarah's father, a conman. Chuck's past gets more attention however, as the long talked of ex, Jill gets reinvolved in Chuck's life. Best of all may be the casting of Scott Bacula as Chuck's father, who does a great job of convincing the audience of his connection to both Chuck and Ellie. Unfortunately, Casey's past does not get an episode that shows him in a new light, like the Ilsa episode, rather a fairly disappointing face-off between him and his old mentor.
Morgan's back, along with the rest of the buy-more crew, and a new face joins the buy-more - that of Emmet (played by Tony Hale, of Arrested Development fame) to provide more comic relief in that bizzare place.
A truly amazing series, with twists and turns abound, and an ending that will only leave you wanting more. BUY.