How I Met Your Mother has always been known for its ability to bring in heart breaking storylines to juxtapose its often daft sense of humour. Marshalls fathers sudden passing and that finale spring to mind, but the first time the shows audience realised How I Met Your Mother could pack an emotional punch was at the very end of the first season finale, when Ted returns home to find Marshall sitting on the front steps in the rain with Lily having left him to go to San Francisco the night before. Lily and Marshall had been established as the most stable and loving relationship in the series and to see that ripped apart at the end of the first season was nothing short of devastating. However, if theres one thing How I Met Your Mother did better than any other sitcom, it was the realism of romantic relationships. Sometimes, things get in the way of the perfect couple and cause them to break up. Of course, we know they get back together a few episodes into Season 2 and eventually get married and start a family, but to see such a dramatic breakup so early on in the series stayed with audiences for a long time.