15 Saddest How I Met Your Mother Episodes

And speaking of sad Barney moments, it wouldn't be a rundown of How I Met Your Mother's most heartbreaking episodes without a shout-out to season seven's Tick Tick Tick. Here, Barney and Robin deal with the repercussions on sleeping together and cheating on their respective partners (Nora and Kevin) before a work get-away.

As they try to act normal around their partners, Barney realises their night together meant more to him than he initially thought, and that he wants to get back together to Robin. Robin agrees, and they make a pact to break off their current relationships for each other.

But then comes the twist, which sees Barney admit his betrayal to Nora and break up with her, and sees Robin unable to break things off with Kevin after he tells her he loves her. Waiting in the bar later on, Barney is heartbroken to find that Robin didn't leave Kevin, and Ted sees him that night removing candles and rose petals from Robin's room, visibly broken.