Chuck is funny. Really funny. The premise, though a little strange, is only a backdrop for some real character driven action comedy. The fight scenes remind me of those in Jackie Chan films, or the movie Johnny English.
The character of Chuck is lovable, and as such instills an instant feeling of empathy in the viewer. He feels more real than many of the characters in big budget dramas. Similarily, the two agents sent to protect him - Sarah and Casey are both easy to like, although in very different ways.
Agent Casey is hardened and emotionally distant, but his scary demeanor allows him to occasionally come out with classic lines, that neither the viewer nor Chuck can tell are sarcastic or not. (The most memorable to me being "I never joke about quiche". Ah, it's funnier when he says it.)
There are many other comic characters in there, such as the creepy duo Jeff and Leister, Chuck's lazy boss Big Mike or his sister's action hero boyfriend Devon (who Chuck calls "Captain Awesome").
Chuck's sister provides some emotional sub-plots as does the buy-more and Chuck's will they won't they relationship with Sarah.
All in all, Chuck is a funny, action packed and filled with refrences to nerd culture (which suits me fine) with a near perfect cast. Seriously, if you like; action; comedy; espionage; drama (ok so less this one); scifi or have any tastes that are remotely nerdy, then you will enjoy watching this. (Also, my mum likes Chuck, and she isn't really into any of the main concepts of Chuck)