What factions gives you a fun boost and why?

[QuintusSertorius]

Migration campaigns, kinda like the one you've done yourself, but by using the "move_character" cheat. Fun ones, are moving greece or eperios to Pergamon, syracuse or massilia. (or alternatively, crimea, but you can move pontos there too). Or moving one of the gaullish factions to thracia/galatia :)

This, basically. I find migration campaigns to play the factions that didn't make it into EB the most fun. Especially Hellenic fusions; Pergamon with its Thracian and Galatian elements, Massalia with Gallic elements, the Bosphoran Kingdom with Scythian elements, Kyrene with African elements.