I'm halfway through season four of Chuck, but they manage to keep things fresh without being obnoxious. The missions, gear, and suspense/cliffhangers show that this show doesn't take itself too seriously.
I really like some of the moral/ethical decision-making and complexities that the characters continually have to make. It shows character development opportunities and makes the characters always interesting, since you get to "know" them a little better each time. I also really like how the show highlights tightly knit family relationships and friendships, although they go through a lot of challenges and dysfunctional situations.
I'm not sure what I'll watch next after I complete the Netflix run of Chuck, but I may probably pick up Psych and Burn Notice since I have liked the couple of episodes I've watched of each but haven't really had time to delve into either. I may also pick up Mrs. Bradley Mysteries with
We'll just...have to see :D