4. Barney (How I Met Your Mother)
Barney is a playboy (forgive the use of that term but it fits). Hes all about promiscuity and having the most legen (wait for it) dary night possible. So why marry him off with Robin? The show uses Barney as a supporting player, in that you cant help but feel hes playing second fiddle to Robin, in terms of emotional screen time. We get to see how shes taking the relationship and all that, but Barney is relegated to cheap tricks, lies and laser tag. Its not entirely believable. Are we supposed to believe that Barney has completely abandoned his lothario ways? Im not buying it. In the style of How I Met Your Mother, we already know that Barney will try and flee the wedding. But then we also know that Robin dances with her father at the wedding, so its pretty much a given that the ceremony goes through. But surely Barneys past will cause an issue between him and Robin? I mean it has to, surely. For a series as consistent and, continuity wise, on point, it would be a massive disservice to neglect this gaping hole.