All of the campaigns to me had high points and low points and missions that were either boring or annoying, in fact when i was opening up maps i'd even skip a mission if i didn't need it to progress.
Fractions was the most fun because of the pvpve it gave, namely AB, JQ and FA. You had a reason to play those, be it for a title for GWAMM or to claim a town, rather than the meh reason you pvp in this game.
Even the small mini missions dotted around were quite fun in their own way.
Hope we get oni.