AMS is just too busy for me. I've yet to have a connection there that didn't feature a long walk through exclusively commercial areas. It's great that they've got the casino and shopping, but I'm really not interested and that stuff just gets in my way. I've had no problems with the place, but it just hasn't made me happier than usual.

As far as European (heck, any) hubs go, I've yet to see anything I prefer to FRA.

Smaller airports are a whole different matter.