TV tonight: 'Big Bang Theory,' 'Mom,' 'Archer'

The Big Bang Theory
CBS, 8 ET/PT
Sheldon and Leonard finally agree to do something their girlfriends want to do — go dress shopping — and somehow end up getting into a fight. Boys, boys, boys: Is that any way to start a new year?
Mom
CBS, 8:30 ET/PT
Mom has turned itself into one of TV's most intriguing sitcoms through its willingness — once common but rare these days for a broadcast comedy — to tackle serious issues, from alcoholism to teen pregnancy to homelessness. But not tonight, as the series strikes a lighter note with a broadly funny, fairly risqué outing that finds Christy and Bonnie facing unexpected romantic complications. For Bonnie, the problem is the sudden appearance of Alvin's ex-wife, played by Beverly D'Angelo. For Christy, the problem is the nice new guy she just met, a neighbor played by Fargo's Colin Hanks, doing very well with a change-of-pace role.
Archer
FX, 10 ET/PT
Of course, when it comes to broad, risqué humor, nothing tops Archer, which returns with a typically amusing episode that strands our hero with a Japanese World War II veteran who doesn't realize the war is over. ("I have some bad news. And some worse news.") Don't expect the plot to make any sense; just enjoy the jokes and another chance to spend time with the world's most humorously self-absorbed spy.