Barcelona won the European championship 2005/2006 so i guess they are the best, we will have to see in the new season if they can be beaten by the likes of Chelsea or Milan .
Liverpool, they managed to win the uefa champions league with many players injured, and now they are building up a great team IMO. Would also look out at Inter, especially if both Juventus and Milan get into Serie B
would be between milan and bayern. both have a lot of success in their own leagues and european cups. other teams are going through a good patch but not much history. i know ajax have 4 european cups, but they havent done anything in 10 years and the dutch league is v weak