Personally, I have mixed feelings on Chuck. On the one hand, I think it’s the most consistently enjoyable show on television. It just makes me smile. On the other hand, it seems pretty clear that the show wants to be something more (as opposed to Reaper, which is content with being light, formulaic comfort food), and I’m just not sure it has enough oomph to pull that off. And when it tries, it inevitably falls short. I respect the ambition, but it frustrates me that the show hasn’t quite been able to live up to that ambition.
As I said in comments, I have the exact opposite perspective on Chuck. I think its attempts to create a larger mythology are stopping it from becoming the truly great light adventure-comedy that it has the potential to be. But what I find interesting is that whichever way you look at Chuck, it’s a show that hasn’t quite lived up to its full potential. It is a goofy action-comedy with spy adventure, light banter, and villainous plots to be foiled; it knows and accepts that this is inherent in the premise. But it also wants to be something bigger and more ambitious than just a light adventure every week; it wants to tell a larger story about Chuck, his growth as a person, the compromises and hard choices people have to make to survive, and the double-crosses and conspiracies going on behind the scenes.
Which is fine, but a lot of episodes, maybe all of them, seem to me to have an uncomfortable tension. The show is still too light and fluffy to be all that it wants to be, yet the broader mythological elements (and the time spent on them) mean that the stand-alone adventure stories aren’t fully satisfying on their own, either. This is one of the potential dangers of combining the arc format with stand-alone stories: the larger story running through this week’s plot can suggest that the self-contained stories are less worthy of our attention, especially since we know the good guys will win. The X-Files got around this by working hard to make stand-alone adventures unique or interesting or gimmicky in and of themselves. But many of the shows that have followed seem to convey the impression that the writers have not quite devoted their full attention to weekly story construction; that was the biggest flaw of Veronica Mars, where the weekly mysteries were often incredibly lame.
Chuck needs to develop some more, and hopefully will; it needs to go in one direction or the other — more ambitious or less ambitious in its overall story. My own preference with a show like this would be for it to concentrate more on the light adventure aspect, just because once they perfect that, the more serious and ambitious stuff can come more naturally out of the strong foundation of good, solid weekly stories. But I can see the opposite argument, that it will never really be all it can be unless it tries harder to make a strong emotional impact and create a more layered world.