It seems a bit hard on Frankfurt. However, I've only ever flown into it and have never connected there, so I can't comment really.
Heathrow depends on the terminal. I hate T1. I don't mind T4 at all.
I passionately hate CDG - and most people regard me as a francophile. Any airport where you don't get another opportunity to go to the toilet after you've passed through the security check has problems.
For all that people give out about Dublin, I don't find it too bad - except for the security queues.
Anyway, to dish out some praise for a change...
Good airports
Rotterdam - A small, but well-organised airport. I love it when I can get a direct flight from Rotterdam rather than Amsterdam - which isn't a bad airport for its size - because everything happens so much more quickly when going through it.
Helsinki - The airport itself works well, but it could do with a better connection to the city centre.
Birmingham - A lot of people will disagree, but it's way nicer than any of the London airports.