The funnest part of The Big Bang Theory these days is seeing Mayim Bialik play Amy Farrah Fowler. Amy has this notion that she should follow societal norms, but doesn't act on the notion actively. In one moment, she's doing her blank stare and in the other, she has a big grin on her face, as dictated by what she thinks she should do in the situation. This leads to a train of laughs when she hangs out with Leonard, and I really liked the main plot.
Of course, it isn't an episode of The Big Bang Theory without some character bashing. The B-plot was one of the worst in a long time, a painful return of Howard being the biggest loser in history. Bernadette sees his behavior in the episode--the weird relationship he has with his mother, references to his weird relationship with Raj, not even cutting his meat--and you wonder why she doesn't run off. The writers cease to treat Howard as a person and instead use him for cheap jokes. As good as Amy was in the episode, I don't think it offsets the awfulness of the rest of the episode.