Well, I have two candidates ^_^

Some years ago, I tried to reconcile with JRPGs, so I bought a PSP game called "Dragoneer's Aria". It was... awful. Terrible. Incredible boring, full of clich�s, with a completely broken magic-system, and so on. Now I can say that "Dragoneer's Aria" managed not only to make reconciliation impossible, but also killed my expectations for the JRPGs in the future. Anyway, I must admit that the music was beatiful ^_^

And, knowing that probably some people would kill me... Ultima 2 Revenge of the Enchantress was a terrible disappointment. I tried to like the game; I loved the first and the third part... but this sequel was extremely confusing, brutally difficult, and very, very annoying. Fortunatelly the franchise got better and better from here ^_^

Also, in a side note...not the worst RPGs I played, but Dragon Age 2 and Oblivion are, without doubt, the two great disappointments I had with the genre.