Holiday comedies are basically a pass/fail situation; almost no movie produced exclusively for people who are already at the mall and feeling seasonally inclined from hearing the Muzak version of "Santa Baby" 18 times is going to be an opus of hilarity. Holiday movies can, however, be really bad (or at least really mediocre, which is arguably worse), so it's not like there's nothing to strive for in the genre. Lucky for Four Christmases
, it passes -- not with flying colors, but not by the skin of its teeth either. It's well acted and it's entertaining -- and who can resist a movie where Vince Vaughn and Jon Favreau are brothers, and Robert Duvall is their dad?...