"Jeff, Who Lives at Home" is NOT a film for everyone. It is very indie in style and features mixed up characters who are difficult, at times, to like. It is far from the sort of thing you'd expect to see from Hollywood, that's for sure.
Jason Siegal stars as the title character. He's a 30 year-old loser--with no job and living in his mother's basement. He sits around smoking a bong and has little going for him other than, down deep, he is still a very nice person. Much of the film concerns him and his brother, Pat (Ed Helms) who is MUCH easier to dislike. Unlike the optimistic Jeff, Pat is caustic--critical and not particularly nice. Their mother (Susan Sarandon) is frustrated with her life...though she has a hard time recognizing this. By the end of the film, events have taken place that both bring them all together and get them all to reassess who they are.
As you can tell, this is certainly not a traditional plot. It's much more like a typical Duplass Brothers film--with realistic but highly flawed characters that you grow to like in spite of themselves. However, unlike one of their films, they apparently impressed someone with money, as this one has major stars and obviously cost much more to make. Not a brilliant film but there are many, many small moments that you'll appreciate. Also, it starts off VERY slow--stick with this one.
By the way, in a supporting part you'll probably recognize Steve Zissis from anther Duplass film, "The Do-Deca Decathlon".