Difficult to see past Trott, Kenny, Murray, Whitlock, Farah, Froome, Peaty, Brownlee (can't remember which one), Lewis and Adams, unless you want to go for the more romantic stories of Skelton, Laugher and Mears (Torville and Dean won it, both as a person and as a team) or Cavendish.
I'm sure that there are many other worthy candidates, but it seems as though you have to be a multiple World/Olympic champion to even be considered this year.
The one I can't think about is the Team. A few months ago I would have said Leicester City, who have invented the term "Doing a Leicester City." However, since then, both the Olympics Team in general and the Ladies Hockey Team have Done a Leicester City".
Although, to be honest, if John Terry doesn't get it again this year (nor Chelsea) it will be a travesty.