Let's rank all treble winning teams in european football history

[matbezlima]

Celtic 1966/1967
Ajax 1971/1972
PSV 1987/1988
United 1998/1999
Barcelona 2008/2009
Internazionale 2009/2010
Bayern 2012/2013
Barcelona 2014/2015

 

[Infordin]

1. Barcelona 2015

2. Bayern 2013

3. Barcelona 2009

4. Manchester United 1999

5. Internazionale 2010

I can't comment on the other two as I don't know nearly enough about them. That Ajax team did win three European Cups on the bounce, so it has a solid case to be #1.