5) Tales of the Abyss (PS2) - The Tales games have long been known as derivative anime RPGs meant for the masses. They've generally been known as quality titles, but there hasn't been a whole lot that makes them stand out from the rest of the genre. Tales of the Abyss provided gamers with a story that, while not completely out there like those of the Shin Megami Tensei titles, was a much higher quality than those of the other Tales games. Characters were interesting, and just about every one of the party members and main antagonists had some surprise up their sleeve. This title makes my list not because it provided anything new - it didn't - but because it is simply a top-quality RPG that got passed over on its release.
4) Persona 3/FES (PS2) - You'd expect that a game late in a console's lifecycle, released after the platform's successor, would simply be a cash-in on the large install base of the system. Not so for Persona 3, a drastic change in direction from any of its Shin Megami Tensei predecessors. Combining life-simulation elements with hardcore dungeon crawling, Persona 3 isn't quite like any of the other RPGs around. Certainly, games developed in North America give players freedom to explore the backstories of their party members, but Persona 3 takes it a step further, allowing gamers to deeply involve themselves with a great number of NPCs. Not only does this provide depth of story for the game, but it also has effect on the battle system - making certain persona stronger based on how you form your social links. While its follow-up, Persona 4, is also a top-notch game, Persona 3 introduced the concept and has an arguably more interesting cast of characters.
3) Final Fantasy X (PS2) - Final Fantasy VII is often said to be the game that introduced cinematic-style storytelling to RPGs (I'd give this title to Phantasy Star IV, but that's neither here nor there), and Final Fantasy X is rightly perceived as the game that introduced real-time engine cutscenes to gaming consoles. Final Fantasy X is the title that popularized many of the aspects that are used heavily in modern RPGs - minimaps, the lack of an overworld, and the aforementioned cutscenes all come to mind. While there might be argument down the line on whether or not this really is worth playing ten years from now, there's no argument whatsoever that Final Fantasy X was the vanguard title for this generation of RPGs.
2) Digital Devil Saga 1/2 (PS2) - Despite their short length, the Digital Devil Saga titles were proof that an RPG didn't have to use a cutesy, save-the-princess storyline to appeal to the RPG fan. Taking place in a post-apocalyptic wasteland, the DDS series combined the quality press-turn battle system from Shin Megami Tensei: Nocturne with extraordinary storytelling and voice acting. These titles weren't the first to provide top-notch voice work or speech actually mapped onto the characters' regular models (you can thank the next game down on the list for that), but much like Chrono Trigger, they take some of the best ideas from the genre and cram them all onto one disc.
1) Star Wars: Knights of the Old Republic (Xbox) - BioWare is hands-down one of the greatest developers of games on the face of the planet. Almost every single one of their titles has launched to critical and commercial success, and games like Neverwinter Nights have become heralds for the kind of tools that a game should provide to an end user. Their first console RPG release, Star Wars: Knights of the Old Republic, is by far their most impressive console title to date. Don't get me wrong, Mass Effect and Jade Empire are great games, but BioWare's fusion of the Star Wars pen and paper RPG rules, their fantastic Aurora Engine (later used in The Witcher), and quality writing not only gave the Xbox a top-quality exclusive, but set the stage for future Star Wars titles to be a lot more TIE Fighter and a lot less Jedi Power Battles.