2. Barcelona
You cannot have a list like this without including Barcelona. Barcelona have dominated over the last 5 years. Mainly due to the fact they had mastermind Guardiola in charge (Now at Bayern Munich). Now, however they now have Gerardo Martino after Tito Villanova had a short reign. Martino has spent most his time managing in South America, playing similar, attractive football to what Barcelona have been playing with. Barcelona's style of play is fantastic. Although, now they seem to be even more direct with their play which means teams won't be able to just watch Barcelona pass it about 40 yards clear of their goal before trying to break through the walls of a defence. Celtic coped with Barcelona relatively well last season. They might struggle a little more this season. Lionel Messi is obviously going to be creating and scoring over the course of the Champions League. Xavi's passing ability is beautiful and Iniesta's ability is unreal. Alba and Alves at full back link up well with the pacey wingers, Sanchez, Affelay, new-signing and wonderkid Neymar. They also have solid defensive, box-to-box midfielders in Song, Fabregas and Mascherano. Pique and Puyol have both continued to impress at centre back over the course of the last few seasons too.