From what I understand, Legendia was made by some outside team and didn't come from either Team Symphonia or Team Destiny. It also wasn't originally planned to be a "Mothership" (main) title, but was supposed to be an "Escort" title. People seem to like Go Shiina's music in Legendia though.

Edit: thought I was replying to KingdomHeartsFan.

Uncharted, GTA, MGS, Gran Turismo and Fallout come to mind.

I know a lot of people didn't really like Pikmin 2, but for me it was perfection.  It was completely packed with tons of crazy content.  Pikmin 3 was really solid and offered a lot of fun, but they just stripped the game of so much of the stuff that made 2 a blast.  So much was improved in 2 only to be taken away in 3.  It's like they wanted to improve the game in some ways so they had to gimp it in others.  Like taking away the c-stick control?  Made the game considerably more frustrating to control.  Also I was just overall disappointed that it could be so short and have so little content.  I always sink well over 20 hours into Pikmin 2, but 3 is just a fun, easy little romp with very little challenge.  With such a simple concept as far as level design goes (dig some rivers, make some ledges, set up some bridges and gates, and plunk enemies and fruit down everywhere) they could have made it huge and a lot longer.  But instead I paid $60 for a game that I feel could have been designed by a handful of dudes in a week.  A simple level editor and I could make something way longer and in some cases better than what I had to wait nine years for.

A lot of people will disagree with me, but I was just disappointed.  It was fun, but not the sequel I wanted.  I feel like they dropped the ball, and so I think overall it was a bit of a dip for the series.

Sonic

Well I understand where you are coming from kind of, but for me it was the best installment of the franchise.

I liked the encouragement of speed runs and maximizing your time.  It appealed to me.

3 Captains was a fun thing that takes time to master, but by the end I was dominating with three.

I thought the bossfights were the best in the series. I liked just about every one.

The music was just so beautiful. 

Flying pikmin squad was a lot of fun for me.

Challenge and multiplayer modes added at least 20 hours of playtime.

Anywho, I can see liking Pikmin 2 better, but I really thought that 3 was a worthy successor. Oh and it was pretty!

Call of Duty.

I can't think of any that didn't have its 'bad ones'.

Agreed. Though I've still got a couple of reservations about the new one, until we see the final product.

I would say 3D Mario is a good candidate as well. I don't know if "improved" is exactly the right word, but they certainly do find ways to include fresh ideas, power ups and level designs each iteration.

Gran Turismo

I agree the OP, MGS has improved in every game. Even though Peace Walker is a portable game I think it has the best story and just the ridiculous amount of content for the game is awesome. I am so ready for MGS V