I absolutely love Gatwick. I've flown from there loads of times to Ghana, Senegal, Gambia etc., often via Tripoli with Afriqiyah.
I used to get there about six hours early, then spend happy moments watching all the passengers passing by, dressed in all sorts of interesting outfits, and the teams of flight crews in their smart uniforms.

There's Gatwick North and Gatwick South, and a little train runs between the two, which I liked very much.

I only used the ordinary cafés, but their sandwiches and snack foods were always delicious. I'd sit and natter to anyone who looked a bit stressed or lonely.
There's also a nice chapel there, multi-denominational, for prayer and reflection.
I love airports, it's in my blood (both parents were in the RAF!)