Fable 2 - I loved Fable 1, but found Fable 2 too easy and dumbed down. Like Fable 1, but without the novelty factor. If Fable 2 had several difficulty settings, I might have enjoyed it more. My little sister loved the game, though, so at least my hard earned money didn't go wasted. And for that reason, I'll be very wary of Fable 3.
Lost Odyssey - I never finished the game, I'm at CD 4/4, but last time I played was like 1 year ago.
Star Ocean TLH: gods, do I hate the characters. The only reason I enjoyed the game was because of the real time combat.
Prince of Persia (the last one) - in the beggining I was all woah! awesome, and then I was all meh, because it's just the same thing over and over again. at least the boss battles add a little variety :/
Mirror's Edge - I only played the demo, but it failed to impress me. I stopped playing after 5 minutes (yeah, I didn't even finish the demo)
Street Fighter IV - I came from Soul Calibur IV, and I love that game. Coming back to SF4, it felt limited (a 2D fighter, I never thought that still existed), because today's 3D fighters feel so much more agile. I played and loved SF2 turbo on the SNES, but I believe that games should always learn the lessons from modern games and not just do that same thing that worked 15 years ago.
Warcraft 3 - I came from Age of Empires, War3 was too frenetic for me, and playing the more forgiving campaign, I failed to see what was so good about the game. I remain a great fan of Age3 and Halo Wars, though