"Perfect on Paper"
Katie Holmes guest stars as the Slutty Pumpkin, a Halloween dream girl from Ted' past.
"Slap Bet"
The gang uncovers Robin's secret past...as a former Canadian popstar!
"Tailgate"
Barney and Ted open up their dream bar, "Puzzles," in the apartment.
"The Best Man"
Barney and Robin take over the dance floor at Punchy's wedding.
"Legendaddy"
Barney finally admits to himself that Bob Barker is not his real father, and he spends quality time with his actual father, played by John Lithgow.
"Of Course"
Jennifer Lopez guest stars as a self-help guru who tries to seduce Barney.
"Oh Honey"
Katy Perry plays a beautiful but dumb love interest for Barney named Honey.
"Bad News"
Marshall is convinced that Lily's OBGYN is actually Barney in disguise.
"Canning Randy"
Robin does the walk of shame the morning after celebrating Halloween.
"The Magician's Code, Part Two"
Barney and Quinn are arrested by airport security when he refuses to open up a box they are traveling with, which is later revealed to contain an engagement ring for Quinn.
"Old King Clancy"
Robin tells the tale of how she hooked up with a Canadian celebrity when she was younger.
"Everything Must Go"
Barney uses Abby (Britney Spears) to make fun of Ted's obsession with monogamous relationships.
"Showdown"
Barney appears on The Price Is Right in an attempt to bond with who he thinks is his birth father, Bob Barker.
"The Drunk Train"
Barney meets his match with Quinn (Becki Newton).
"Hooked"
Ted can't seem to seal the deal with a girl (Carrie Underwood) who constantly keeps him on the hook.