What Gravy said. >_>
Ted Lewis wasn't great, and Eric Stuart's James voice from Kanto through Johto remains my favorite for the character ever (even counting Miki Shinichirou). But right at the end of Mater Quest, something went horribly wrong. Nearly every time James opened his mouth in AG, I wanted to cringe, and when the VAs changed, James was the only character I wasn't too upset about beforehand because I hated Stuart's AG version so much. It was huge disappointement when his new voice sounded just as bad or worse.
Rachel Lillis' Jessie was always terrific (bar the first, I dunno, ten episodes or so), and she was easily my favorite voice on the show. Maddie's Meowth was brilliant as well, and they both top the TAJ voices for me. I still really miss those two, as they just fit their respective characters perfectly.
And I don't mean to demean the new actors or anything with this, because they're trying hard and making progress.