Final Fantasy 2 seems to come to mind with it's incredibly cheesy, static storyline. I liked the weapons/magic levels, but the dodgy storyline and "ask" system can go straight to hell.

(I'm talking about the Japanese FF2, not the FF2 on the SNES which was FF4)

Pro Evolution Soccer 2008 and Assassin's Creed Revelations

Well if we look at sequel as the second game released in a series I can't think of any off the top of my head that I was extremely dissapointed in....wait nope got one Red Steel 2 I played it maybe half an hour and thought the first one was way better. RS2 shouldn't have been in the Red Steel IP at all.

As far as sequels go Animal Crossing City Folks was the biggest dissapointment from Nintendo I have ever experienced. Sonic next generation was horrible as was Secret Rings. Bomber man 360 was terrible. Bubsy3D.

Their are countless horrible sequels. Though the absolute worst one I have personally played was Sonic Secret Rings tied with Bomberman360.

Its laughable that any of those first party titles are on the list. None of them were bad games.

I never said they were bad games, all of them were great (well, except Zelda II). I just wished for more improvement over their predecessors.

Edit: Wait, my opinion is laughable? Grow up dude.

I'll go with direct sequels to the origional titles................. (Part 1 great, part 2 not all that good)

Galerians>>>> Galerians: Ash

God of War>>>> God of War 2

Condemned>>>> Condemned 2

Crackdown>>>> Crackdown 2

Devil May Cry>>>> Devil May Cry 2

Just off the top of my head.

I said it was laughable to say they were among the worst which is the topics heading. Most dissapointing means a bad game none of those titles could possibly be ranked as a most disappointing by anyone who enjoys the franchise at all.

This has the potential to be a very long, long list, but here goes

Parasite Eve 2 and the astoundly abismal The Third Birthday (The original Parasite Eve is one my favourite games of all time)

KOTOR 2 (Mostly because it was extremely rushed)

Dragon Age 2 (What the F did they do to the franchise...)

Grandia 3 and Xtreme (Same thing that DA2)

Alundra 2 (It shouldn't even be called Alundra since there's nothing left from the original game)

Final Fantasy II (Not to be confused with FFII US, which actually was FFIV. Worst FF game of all time)

Sonic Adventures II (The first one was one of my favourite games of the Dreamcast)

Micro Machines V3 and 4 (Why did they forgo the amazing R/C top view? )

Shadow Hearts: From a New World (This shouldn't be even considered a Shadow Hearts game)

Medievel II (Extremely dissapointing sequel)

Chrono Cross (Worst sequel of all time)

I think I should stop here...

I only buy high quality games and out of those these were the most disappointing. I really don't see the problem.

Any Sonic the Hedgeog sequel after Sonic & Knuckles.

Red Alert 2 - The first one was awsome and while the sequel was alright it was far from as epic.
Final Fantasy X-2 - I don't even remember what this game was about....
Metroid: Other M - Had some design flaws that just shouldn't be anywhere close to a Metroid game.
Heroes of Might & Magic IV - Wha-what? *goes back to Heroes 3*
Empire: Total War - I thought Total War + 18th century would be amazing. I was wrong...