In one word, this show is fun.
From the teaser, to the entertaining title credits where Josh dances a funny little jig while he cooks up the name of the episode (Spanish Eggs for example), to the final scene, this show is all about the humor to be found in our own quirks and our quirky relationships with others...Josh and his first boyfriend Geoffrey, his dad and his Thai girlfriend Mae, his mom and his aunt, Josh and his aunt, Josh and Claire, Ted and Nev, etc.
The other thing that makes this a joy to watch is that the cast clearly enjoys what they're doing...it shines through their portrayals. There are also a few scenes where I swear they improvised, and improvised really well. Think 'Arrested Development meets generation Y'.