No such thing as fun gcse tbh, all of them are hard work.
For me the easiest was music as I already played two instruments before starting the course, enjoyed composing and knew a decent amount of music theory so that obviously helped, along with the fact that I rarely if ever got set homework. I can see how not everyone would be able to take music for gcse though, and not everyone who does music gcse will get set no homework, I’m sure my school is an exception!
If you’re choosing subjects, it sounds really cliche but seriously do what you enjoy, it will make the two years so much less painful!