I'm going to hijack this topic and post my planned party. :P If you beat every chapter you get 69 job points, which can master 4 jobs with one point remaining. So I based my builds on the combination of 4 jobs! I won't post every ability they'll learn, but I'll point out the notable things that drew me to the jobs. :)
Sol: Dragoon (Warrior+Monk+Dragoon+Knight) => Two-Handed Grip, White Wind, Mighty Wall, Maximum White Magic, Final Heaven, Full Cure
Sarah: ??? I'm stuck on this one!
Aigis: Knight (Warrior+Monk+Bard+Knight) => Two-Handed Grip, Aura, Hastega, Mighty Wall, Maximum White Magic, Esunaga, Shock, Final Heaven
Nacht: Ninja (Monk+Ranger+Dark Knight+Ninja) => Dual-wield, Long Range, Smash, Barrage (it's not called that but I dunno how to translate)
Diana: Ranger (Monk+Thief+Ranger+Dancer) => Double Item, Phantom Rush. She can equip the Auto Crossbow, which hits all enemies. When used as an item it has a Barrage effect, when combined with Double Item, she can get the effect twice for an instant free 6 hits!
Not to mention that Fusion Abilities add to your arsenal so you get some moves without having the traditional class that the move goes with, such as some spells that usually would require a Blue Mage. And yes, one reason I really want to play with the Red Mage class in this game is that they're basically a hybrid of the FFV class, the Magic Fencer and Celes.