It’s been ages that I have watched the anime so I will only rate those that I actually remember from way back when. Frankly, I was never too fond of the Japanese intros. The outros were way funnier and better I think.

1.) Aim to be a Pokémon Master… the classic theme.
2.) Ready Go! … Soothing.
3.) Advance Adventure … A rather mediocre remix oft he original intro. Music’s too loud compared to the singing.
4.) The Rivals … This one is pretty bad in my opinion. It has a very weird rhythm.
5.) OK! … Way too fast and over the top. The singing doesn't sound fitting with the tune.