Best RPG Systems

Character swapping

Judgment Ring + Fusion + Combo + Sanity

ATB, magical attacks have an area of effect and enemies are constantly moving, every character has an elemental attack and enemies have elemental weaknesses, there are combine attacks between character pairs or triples.

A very unique side-scrolling action battle system.

Job system + two skills can carry over from another job

License grid (zodiac): it's basically FFX's sphere grid, but slightly more open and affects what you can equip too + gambit system: so you can actually control everyone in your party even though you control only one in-battle.

Junction system, you equip GFs and level up skils till you get them. It customizes everything, even battle commands.

I feel like every character has a different form of progression

Sphere grid. Add abilities to weapons and armor.

Skill system.

Weapons give skills. It's like Final Fantasy IX, but in Vesperia the skills are more useful (in part because it's battle system is action-based) with many skills that you clearly see doing something in battle or you yourself use them.

Materia system

Similar to FFVIII, the summons (espers here) give you the customization, here stats and magic. The characters are all very different and the equipment almost always has some relevant extra effect.

Weapons give skills