I love Francois Ozon's films. Together with this, I have seen all his feature-length work (Sitcom, Criminal Lovers, Drops Falling On Burning Rocks, Under the Sand, 8 Women, Swimming Pool). "Sitcom" is the film by him that I found the most bizarre and unsettling (even though I had some good laughs). The ending was a bit too much, but otherwise, I quite liked it. The atmosphere and the bizarre events sometimes reminded me of "Criminal Lovers", that he made immediately afterwards, but with more focus on black humor than in the latter.
The whole way through, the story of "Sitcom" reminded me of Pier Paolo Pasolini's "Theorem" (Teorema) - much more than of Bunuel's "The Discreet Charm of the Bourgeoisie", already mentioned here. In Pasolini's 1968 film, a strange visitor unsettles the life of an Italian bourgeois family: after he leaves, the daughter loses her mind, starts lying catatonicly on her bed and has to be transferred to a mental institution; the mother, in a desperate urge for promiscuity, picks up handsome young men on the streets for sex; the maid goes back to her village and becomes a levitating saint; the son discovers his talent for painting (and probably realizes that he is gay); the father at first seems not to be affected, but then he also succumbs to the influence.
Ozon's film seems to take up this motif and transfer it to a very-very black farce and a parody of American sitcoms (I love the set design with all those bright colors!). People here (especially the mother) always try to "talk things out" like in the sitcoms, but it doesn't really work, because the environment is/has become so different.
At the very end, though, everyone seems to have found themselves at last: from a dysfunctional family, they have apparently become a happy family again - though not exactly in the traditional, conservative way. But the white rat is still lurking everywhere...