Rhapsody: A Musical Adventure is pretty much what it says on the tin. Its a musical RPG by the same team that went on to do the Disgaea franchise. This game is surprisingly turn based though.

Shin Megami Tensei Devil Summoner: Raidou Kuzunoha vs. The Soulless Army pretty much plays like a detective simulator. There is an Action-RPG battle system (well a bad one at least) but the bulk of the game really come into play as you explore the streets of Tokyo solving mysteries with the aid of your demons which can influence people's emotions, read minds, explore locked off locations, and other useful tricks. It's the part of the game I really enjoy especially since the game plays in an episodic format.

Penny Arcade Adventures: On the Rain-Slick Precipice of Darkness Part 1 is certainly more adventure game than RPG. It does allow you to create a characters, choose dialogue, and has turn based combat but so much of the pacing and presentation feels like a cool retro adventure game from back in the heyday of LucasArts.

Steambot Chronicles - Really hard to describe this one, RPG with choices and customization, yeah... but it also has an odd mecha combat that feels more like a bad action game. Also, you can become a musician and make money by playing different rhythm games based on the instrument you're trying to master. It was an odd game...

Vagrant Story - Can't really think of a game that comes close to this title in overall design. Perhaps Parasite Eve but even that game was more cinematic design vs. the dungeon crawler VS ultimately is.