How I Met Your Mother is a show with a simple premise: the protagonist narrates to his kids the story of how he met their mother. The show takes place in the present day and concerns the adventures Ted Mosby (played in the present day by Josh Radnor and in 2030 by Bob Saget in voiceover form) and his friends have in New York City.
His friends include the permanently suited up Neil Patrick Harris, playing the legendary Barney Stinson; Jason Segel and Alyson Hannigan as man and wife and Cobie Smulders as Robin Scherbatsky, Ted's former lover.
The framing device allows the narrator to comment on past events, since he has the benefit of hindsight. It also has Saget filtering certain words and concepts for his kids, such as the 'Grinch' episode and their time spent experimenting with 'sandwiches'. The idea is that it all builds up towards Ted meeting his then-future wife.
The show has recently started airing its sixth season in the states and has enough episodes for syndication.
If you are unfamiliar with the show, then don't worry: us die-hard fans haven't learned much about the titular mother either. We have glimpsed her foot and learned that she was in a class Ted taught (both of them in this season if I recall correctly). There is some other stuff as well, but not that much.
The fifth season has some great episodes, which are naturally included on the set (labelled the 'Suited Up Edition'). "The Wedding Bride" stands out as one of them and is easily my favourite from the season. Another one I had forgotten was on here is "Say Cheese", which is a pleasure to watch again. "Girls Vs. Suits" is also excellent, as befits the show's 100th episode. It includes a big song and dance number, which is included in its entirety on the DVD bonus features.