I love KOF 2002/2003!!!!!
In King of Fighters 2002, i badly want to play as Billy Kane, Kula, K'9999, and Geese Howard. It is a shame that the 2d graphics aren't as cool as Capcom Vs Snk, however it was still 2d and that is my favourite over 3d. As i was able to play as Billy Kane and Kula Diamond, i enjoyed playing as the bonus characters Gesse, Goenitz, and Orochi Iori in the PS2 Version. The down side was pulling off Angel's super moves and combos.
I was more interested in getting King of Fighters 2002, however i grown to love King of Fighters 2003. The best characters of the game are Ash, Shen, Duo, Adelheid, and Gato. Iori's Leader Combo was the coolest finishing combo in this game and is now my favourite.
I would recommend getting these games, because they are the best King of Fighters series so far in their original 2d forms.