For me, I personally think three RPGs have done combat the best in their fields.
Dragon Quest has pretty much perfected 'Turn Based' combat. Utilizing a system that balances difficulty with function. Boss battles are a challenge because you need to utilize everything to defeat them. Not just spells and physical strength due to higher levels, but items and even a sense of 'skill' with the turn based system. And even the random encounters in the field can kill you if you don't equip the right gear and utilize the proper gameplay methods to defeat them.
http://www.youtube.com/watch?v=LRbI2fIVh4U
Suikoden has been around since the early PSX days. Indeed, it was one of the first PSX RPGs on the scene. Its arguable to say its Rune system inspired Materia. However, its the basis of its Rune system, and its simplicity mixed with pure versatility, that makes it so great. The ability to take a Rune of any type and, based on the characters level, have those spells already available to use right after equipping it on that character. No excess leveling for additional spells, no unlocking new abilities, no combining with equipment to unlock hidden abilities...ready to go, spells. And it doesn't become an overpowered system, even when allowing characters to equip up to 3 runes (12 available spells). Add to this nearly every kind of Magic there is From Elemental, Summoning, Death and even Creation magic, the runes pretty much filled the full spectrum of the 'JRPG' standard of what magic should entail. And when your cast fills 108 characters all with unique play styles and you can use 6 of them in battle....that is one fully customizable RPG.
http://www.youtube.com/watch?v=VQ0aGdLmHn0&feature=related
Last but not least is Diablo, setting of a system of 'clones' in the RPG/Hack n Slash genre. And who could blame them, as this is one of the few games that makes 'grinding' actually fun. There's not a lot to say about this game, its more of an experience than a game to examine. As well as a game that combines multiple genres into one. But its also more of a game that successfully melds fantastic gameplay with good production values and artistic design. And when all three of those come together....you have magic.
http://www.youtube.com/watch?v=hrVHr1AwbL4
I would like to add that I have a bias towards RPGs that follow three things however. RPGs that focus on Characters, gameplay and Item Collection over 'story' or graphics. Of course story and graphics are great. The game series I mentioned do not slouch on those things at all. But they do not focus on them.
Six upcoming games you should look into:
