I have to agree with VintageKrug about Frankfurt, for all the reasons he gives, but a close second is the Zurich Airport First Class Lounge. Virtually all the same facilities but the food choice is better in FRA.
My big gripe is that they will no longer keep your coat for you. This was a very useful service if traveling to hot countries when departing during a cold European winter and saved having to carry (or pack) it in sweltering heat.
The excuse for abandoning this service – 3 guesses – “Security”!!! Just how dangerous can an overcoat be???