I tried to play many profiles, but they seem so vaguely unhuman. Even an 8-year old acted different than an 8 year old Chessmaster AI.
I tried the standard Chess Titans that comes shipped with Vista, and offered me a more balanced and logical game, although it beat me.
I tried Chessmaster 11 playing against the chessmaster himself, it gave the impression im really playing with a human. Why are the lower ranked personalities so awkward to play with?
And what's the best one to play as a complete beginner?

You went out and played an 8-year old just to see if it played different than a personality?

Personalities are an attempt to "dumb down" the chess engine... it wouldn't be any fun for a beginner to continually lose against the TheKing playing at full strength.

Many personalities are designed with certain flaws and quirks - just like we humans have. Despite this, keep in mind that you're still playing against the computer.

As a beginner, start with a lower-rated personality (you can read the information about that personality in the 'Select Personality' dialog). Then, at the end of the game, read the post-game analysis... that will give you a suggestion on what personality to play next.

Yeah, I actually played with an 8 year old. His moves seemed more logical and based in reality (at his level of thought) than the weakest Chessmaster Oponent, Casie, rated at 23!

P.S. Is it possible that the engine can "improve"? I made several mistakes on purpose, in the opening moves, and the AI failed to capitalize on this. When I repeated it in a different game with the same oponent, the same. After the third repeat, it never makes the mistake again!