Where would you recommend for a short spotting trip (a day or two) in Europe in January? I would normally choose between AMS, DUS, FRA, ZRH or GVA, but won't in this instance because of the (almost certain) awful weather.
So - somewhere warm.
Also, I'd like it to be quite busy, either with a variety of airlines and aircraft or not.
I won't have a car so somewhere I can spot in (airside or landside) or close to the terminal is needed.