Are any of the Pokemon animes actually any good? And do they require being watched in order?

In my opinion all except DP range from watchable to good.

I might check out Best Wishes and XY then as both seem as standalone as possible.

Really? DP was one of the few seasons I could tolerate.
Indigo League: Watchable (Cheesy, but still watchable)
Orange Islands: Depends on how you like Tracy
Johto: Please god let it end. WHY IS IT STILL GOING!? *Cries*
Advanced Generation: If you can survive an episode without wanting to introduce May to the metal end of a shovel, it's still unwatchable.
Battle Frontier (AG Part 2): A step up from the AG. Watchable.
Diamond/Pearl: Watchable. It drags, but it's watchable.
Best Wishes: Fairly decent.
XY: Haven't seen.

The rest are spin-offs, like Pokemon Chronicles and the Ranger special.

Mystery Dungeon: Team Go-Getters out of the Gate (I think there was a second MD spin-off, unrelated to the first, but I'm too lazy to check) and Origins are completely unrelated to the primary anime.

I'll look into D&P then as well!

I've seen everything so far bar Best Wishes, which I dropped after about 10 episodes. Every region suffers from a drag factor (Johto especially, despite my love for it), but I just found every new character introduced in Best Wishes completely unbearable and Ash's stupidity reset even more obvious than usual.

That being said, I would like to go back and watch the Team Plasma stuff. Is that worth the watch?

I'm enjoying XY so far. It's only 3 episodes in. Though I wish there were better subs.

I had committed myself to watching Pokémon all the way through from the beginning. It was going well up until I got to Battle Frontier when the voices changed. The start of the change was REALLY REALLY bad. And then it got better a season later, but I didn't want to skip, so I just stopped. I haven't touched the anime outside of the movies until now.

Though, if I could find the entire series subbed, I could/would watch all of it. But that's hard to do with the older series. I may try to look for Battle Frontier onward so I can actually watch it. I've gotten used to the JP voices anyway. Even Meowth.

I'm thinking maybe I won't bother with Pokémon anime after all, except maybe X & Y but I can only seem to find dubbed episodes.

Goddangit I wish I could get online to have a chance at all these Vivillons. ;_;