I remember I started watching The Fairly OddParents! around mid 2007 but joined the wiki in 2014.
I think Seasons 0-8 are great. Seasons 9 and 10 are mediocre seasons but not as bad as critics make them seem. The live action movies are dumb and pointless. I don't get the hate for the later half of the series or the hate for any of the main characters introduced in the later half. I do think Cosmo should have kept his lower pitched voice from the early seasons though.
I liked Poof from the start but Sparky and Chloe grew on me over time. I think Poof should be a main character again and Sparky should return as a recurring character. A.J., Chester, Francis, Anti-Cosmo, Anti-Wanda and the Pixies should also return. Tootie and Trixie do not need to return.
Underused characters like Vicky and Mark Chang in recenter seasons should make more appearances like in the old days.
I hated the ending of Channel Chasers because the writers made Timmy leave his kids with an evil Vicky robot. Even though I don't count the ending as canon anymore I still find it to be gross.
As for now I find Chloe as a meh character but I don't really like the idea of Timmy ending up with Trixie or Tootie because Tootie is a stalker and Trixie is a snob to Timmy.
I liked the switch to HD animation but I hated the switch to flash animation. I think Chloe's theme song was unnecessary.
It makes no sense in my views they removed Poof and Sparky from Season 10. Get writers that know how to use more characters and write with them. Butch Hartman should think twice before removing any characters.