Philadelphia Eagles:
In my personal opinion the logo has improved over time. The look of the Eagle logo improves by every change and I think the current Eagles logo in use is the best by a mile.
Jacksonville Jaguars :
I like the Jags, they are giving up five regular season home games to play in Wembley after all. I like both logos equally, I don't think the logo needed to change but the new logo looks more vicious and serious.
Miami Dolphins :
The first logo is terrible in my opinion, it has improved though. I don't like the new logo very much though.
Arizona Cardinals:
The Cardinals have called both Chicago and St.Louis home before moving to Phoenix, Arizona. The relocations have added to all the logo changes. The Cardinals newest logo though is by far the best they've have and they manage to make the bird look aggressive.