That depends on your personnal preferences. One thing for sure you have plenty of choice here in Qatar. I prefer Squash, but on my compound there is swimming, tennis, basketball, billiards, pool, Fusball.

The Aspire zone has a plethora of sporting opportunities in one central area. In addittion there are numeroud Karate clubs, Taekwando and there is a Golf club, numerous football clubs, rugby. Losail race track has a bike club and a moto gp club etc etc

It is dependant on your location, time, interest and abilities but no shortage of opportunity thats for sure.