So what video game series that you think start off great but went down hill later on? For me it would be:

Crash Bandicoot: I loved Crash 2 and Crash 3 on the PS1 as a kid, and I still love them today. Crash Team Racing and Crash Bash on the PS1 where also great as well IMO. After Universal Interactive Studios took over the series then the series started to die with "Wrath of Cortex" back in 2001. "Crash Twinsanity" was better which is hardly saying much. Nitro Kart was fun but it was nowhere as good as Crash Team Racing for the PS1, and I never care for any Crash games after Twinsanity.

Final Fantasy: I used to be a hard core Final Fantasy fan and I loved FF1-10. I thought FF9 was a good game, and I loved FFX too. Things went down hill after FF12 because I thought Final Fantasy 12 lack everything that the past games did and I hated the new gameplay. FF13 try to bring back the classic game feel of the series and the gameplay was much better. But the story and the overall game itself was a major letdown. I think I'm not going to play anything after FF13 unless they bring back the classic gameplay and feel that FF1-FF9 had.

Mortal Kombat: I did enjoy the 3D games (MKDA, MKD, and MKA) but I think the started to play less like Mortal Kombat and try to be more like other 3D fighters like Tekken and Virtual Fighter. Most of the newer characters where so forgettable, and I never like how they started to kill off characters like Jax, Johnny Cage, Sonya, Liu Kang in MKDA. I'm glad that the new game in the series went back to the roots and made it worth playing. Good to have 2D gameplay in the series again for the first time in almost 14 years.

Pokemon: I thought the games kind of lost their charm to me with G5 since I don't think any of the Pokemon feel the same compare to the Pokemon from G1-G4. I feel like that I can't get into any of the newer characters or the new Pokemon at all.

Sonic the Hedgehog: Sonic is a big one and I thought "Sonic Heroes" was the last good Sonic game. That game was a lot of fun to play and I had a great time playing it when I used to own it for the PS2 back in 2004-2005. Shadow the Hedgehog could have been a great game if it was not for the awful camera angles and if the guns where not so useless. Sonic '06 was awful game and I give up half through the game. I also think Sonic and the Secret Rings was hardly a better game and I never play any Sonic game after Sonic '06. I hear Sonic Colors was great though.

Spyro the Dragon: The first three games where my all time favorite games as a kid and I still love them today as adult. While some of the GBA games where okay, but the series really started to suck with "Enter the Dragon Fly" back in 2002. That game was awful due to its terrible gameplay, lame story, and the long loading times. I stop playing Spyro after "Spyro: A Hero's Tail" since that game was so boring and was hardly any better then "Enter the Dragon Fly". I never play any of the new games and I do not plan too.

Tony Hawk: Tony Hawk 1-3 where awesome games and the last great Tony Hawk game to me was Underground 2. After the Underground games ended, the series started to suck and it seem like everyone started to play like the same. American Wasteland was fun but it was nowhere as great as Underground 1-2 or the first three Tony Hawk games. I thought Project 8 sucked major balls and I stop playing the games since then.