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4kids had the best voices and dialogue. If a joke didn't work because it's a Japanese cultural thing or a word pun, 4kids made it into a joke that was atleast attempting to be funny (or was really funny). Team Rocket was also much more bearable, they were more like stereotypical cartoony villains but in a good way.
Team Rocket from TPCi are just two adults who are these parents who try to talk hip and cool but fail and that doesn't work for Team Rocket. Tom Wayland has said it's because Team Rocket is actually really boring so they wanted to spice up things, but this doesn't work.
The insane amount of music replacements of TPCi is also getting rediculous. I mean I know 4kids tended to go too far as well, but atleast they tried to fit the mood.
Also the voices, while kids won't mind I guess, are unbearable. They can't act and really hit the emotion as well (which is what 4kids was able to pull off). I mean Jessie is kind of okay because she atleast tries to sound like her 4kids counterpart and Ash really tries, he really does. But James, Meowth, N and the voices of some Pokémon are inexcusable (Chimchar, Piplup, ...)
Really for some reason, the only current voices that stand out to me, are Bonnie and Shauna. Bonnie because she really tries to perform like her Japanese counterpart (not as cute, but still like a little girl) and Shauna just sounds like this really sweet friend.
Original will always be better though.