The Legend wrote:How I Met Your Mother I think would have been a better concept as a movie than it was as a TV show so I'd definitely say that one.
It sounds like it would work based on the show's title, but I actually don't think How I Met Your Mother would work as well as a movie. What made the show great during the early seasons was the mystery, the continuity nods, the nostalgic tone, the parts of the story that had obviously been slightly altered either for embellishment or to hide something from the children ... I think a lot of that would be lost in movie format.
A movie would probably also iron out some of the flaws of the television show (particularly those that developed the longer the show ran), but it would eliminate a lot of the magic. Just my opinion though. I'm weighing in on this one because I had briefly considered bringing up How I Met Your Mother as an example myself, before deciding that I wouldn't be too optimistic about it.