On levels where the Government does matter, Fascism is a good choice when you have only a limited number of cities (~ <20), but all or most of them are Metros. You then can support an insane number of units. Still, many players will prefer Republic in such a situation.
However, since you surely will use all those units to double (or more...) your territory, and then either Communism (in wartime), or Republic/Demo (peace) is always superior.
So IMHO only REL Civs do benefit from Fascism for some time.
Also, IIRC Fascism+IND means 1-turn RR...
Conclusion:
Top Civs for Fascism:
Egypt
Japan (MIL since you're fighting anyway, 20sp Barracks)