Starting a thread to talk about JumpStart voice actors, feel free to comment!
Well, I'll start with one of my favorite characters, CJ. I especially like Kevin Schon's performance, he voiced CJ in the JumpStart Reading/Math for Second Graders games, and I *think* the original JumpStart 2nd Grade. There's just a kind of charm to his vocal performance, it's not too over the top and personally I think it fits CJ's personality in those games really well.
I also like the voice acting for Eleanor in the video JumpStart Preschool: Who Left the Juice in the Caboose?. I can't remember the name of the voice actress, but she appeared in a live-action song sequence towards the end of the video, and I think she also voiced Eleanor in JumpStart Around the World.