I usually do my research before buying games, so it's very seldom that I actually buy a real stinker.
That said, my vote would have to go with nearly every Final Fantasy game I've ever purchased: 4 through X-2. (And I'll include Chrono Trigger in there for good measure, too, since it uses basically the same combat system.) I used to have a ROM of 1 for the NES that I enjoyed, and 3 for the DS was half-decent, but then they started using that slow-as-hell ATB system, which is just awful. I've never played an RPG where combat goes so slowly. And it might actually have been decent if your actual turn-taking was anything more complex than, "press X to attack."
Now, I love me a good JRPG, and I've played the hell out of a ton of Shin Megami Tensei, Shadow Hearts, and Tales games, and - most recently - DQ8. But I like my combat to be more than waiting, followed by a single, non-twitch-based press of the X button, followed by even more waiting... etc.
"'Casual games' are something the 'Game Industry' invented to explain away the Wii success instead of actually listening or looking at what Nintendo did. There is no 'casual strategy' from Nintendo. 'Accessible strategy', yes, but ‘casual gamers’ is just the 'Game Industry''s polite way of saying what they feel: 'retarded gamers'."
-Sean Malstrom
