Season 5 of How I Met Your Mother went out with a whimper. In "Doppelgangers" Marshall and Lily struggle with the decision over whether or not try for a baby (which they've maturely left up to the off chance of seeing Barney's doppelganger). Robin finally chooses love over a job and ends up heartbroken when Don chooses a job over her. Ted dyes his hair blonde. And Barney embarks on a quest to sleep with a woman in every country ("You're doing surprisingly well in the Baltics").
It wasn't a bad episode, but it wasn't a great episode either. Robin's grand emotional decisions are getting a bit hard to tolerate, and Marshall and Lily's repeated conversations about "being ready" and the ever-so-elegant "put a baby in my belly" phrase failed to either amuse or to be interesting. Finally there is the issue of the laugh track, which I'm usually able to ignore, but in this episode actually it ruined a joke a by coming in too early and too aggressively for the audience to figure out the joke for themselves. See this failed laugh, which happens right after Ted and Robin back away from kissing each other:
Typically season finales of How I Met Your Mother have followed the standard sitcom rules, closing with larger-than-life plots and annoying cliffhangers. This season finale seemed somewhat unconventional as it was lacking many of the commonplace "watch Season 6" teasers. Perhaps creators Craig Thomas and Carter Bays are comfortable enough with their show and their audience to just trust that viewers will return for Season 6 not because they've been forced to wonder whether or not Don and Robin will work things out, but because they enjoy watching the charismatic leads do their own thing.