Rachel referencing Hugh Laurie's line
On the episodes of The One Who Could Have Been on season 6 there are lot of references to past episodes.
There's one I have only noticed now that I'm rewatching them after some time.
When Rachel tells Joey she's not a good person because she's in his apartment while she's married, she says that she's "a horrible, horrible person".
That's the same line Hugh Laurie's character have when he's on the plane with Rachel and she's telling the story of why she's going to England.