Arrested Development
I've watched all four seasons over the course of probably a couple of weeks, which is pretty fast for me, since it's rare for me to find a show that engages me enough to watch multiple episodes per day. As you can probably guess, that means I like this a lot. The show has long been a cult hit, and I remember seeing it briefly when it first aired over here back in the day, but I was in my early/mid teens at the time and I just thought it was a "show about adults talking" which was the kind of thing I found intensely boring. Cue my surprise when I found it on Netflix and discovered that it was in fact a spectacularly complex farce with densely packed layers of jokes with a cast of well observed characters.
Since the original run is so well known I won't really talk about it much, except to say that every episode is hilarious. Even the Wee Britain arc, which starts off cringe inducingly bad, but turns out to be a brilliant satire on American sitcoms using non-British actors to play British characters, is great. The fourth season is quite a bit different, mostly owing to its structure, which is about showing the same period of time (specifically the time since the original run ended) from the perspective of each character, and at first it seemed kind of slow and depressing. It's only when you start to get into the structure and see how all the different perspectives come together that you realise it might even be the best season yet (a 5th is supposedly shooting or will be soon), and the way it deals with the characters coping with the fallout of the original finale mixes hilarity and poignancy in equal measure.
I've also been watching It's Always Sunny in Philadelphia, and I thought I'd mention it here because these two shows seem to get put together quite often. It is taking me a lot longer to watch, I started watching it before Arrested Development, but I'm still only a few episodes into the third season. I enjoyed the first season a lot, and quite a few episodes of the second, but the third has been slow going and it feels like the show has very quickly become less about self-obsessed people trying to get away with doing questionable things for their own personal gain, and more about the writers running out of ideas and just throwing together ridiculous situations that have no basis in reality whatsoever. The overreliance on the McPoyles, a family of inbred weirdos, for shock/gross-out humour, gets old very quickly, and the main cast have gone from being narcissistic and petty yet still relatable, to being alienating and unfunny. There are still isolated laughs here and there, but the engine of the show seems to have run out of steam rather quickly, and I think this is because the characters are more a collection of superficial traits and gimmicks, and the greater extremes they reach the thinner those elements are spread, exposing a core with nothing much in it. Maybe it finds its edge again later on, but it would take some doing.
I'm really not sure why the two shows get compared. Sure they both centre on flawed people who get into ridiculous situations via an admixture of self-absorbed hubris, misunderstanding, and sheer stupidity (but then what is any sitcom ever if not variations upon or even straight repetitions of this theme), but Arrested Development has strong characters with complexities which give rise to those situations, and there is always an underlying sense of humanity. But in It's Always Sunny the ridiculous situations seem to arise because they must, otherwise there would be no episode, and with the characters becoming harder to care about as they become further removed from reality, each episode just seems to drag on longer than the last. Seinfeld, often seen as a predecessor to It's Always Sunny, was always about complex dissections and send-ups of social faux pas, and no matter how dated it may seem today (it was the great cutting-edge laughtrack sitcom that effectively killed the genre as a viable format for "mature" comedy going into the 2000s) it still far outstrips its would-be successor in subtlety and in its understanding of why people do stupid things. So, too, does Arrested Development, simply the most brilliantly crafted comedy I've encountered in a long time.