I must admit, I don't really enjoy sport anime, probably because of my own lousy athletic ability.
However, Prince of Tennis did catch my attention for a little while; not enough to keep my attention for the rest of the series, seeing as I never managed to complete the anime, but I did enjoy what I did see.
I know next to nothing about Tennis, so I guess I can't say much about the Tennis aspect of the show or how accurate it is. I can, however, talk about the characters. Ryoma Echizen is really the main character. And I must say, for a kid, he was pretty cool. While Sakuno annoyed me, she was a good character either way.
I suppose if you're a tennis fan, you might really like this show. It wasn't one for me though.