PoT definately has my vote for the best sports-anime. They have a great mix of good music, nice setting and tennis shots that people can only dream of.
But I do think that its not so popular here at the forums *sigh*. I mean like, the last OP was probably one of the best anime songs I've heard, yet Im probably the only person even mentioning a song from PoT
Of course, the animation/drawing isnt that good compared to other animes, so perhaps thats why its so shunned in AF...