Probably the best writing in a Video game,but the script is sometimes to whacky and stupid. But actually that's make it charming in my opinion. I also want to mention the God tier soundtrack from Shinji Hosoe (please listen to the Rave Racer soundtrack also really fantastic but yeah his most well-known work is maybe I think Street Fighter EX2).
I personally recommend playing the DS version of the game for the definitive experience.