This is without a doubt my favorite game ever. Even though it's kinda old and the graphics aren't in the same league as Here Comes the Pain or Ruthless Agression it still is enjoyable. The roster is huge and the fact that you can change the appearance of anyone is a big plus. This game also gives you lots to do by getting all the secret characters and all the items in the Smackdown Mall.
The story mode includes storylines that are still used today and the game is super difficult like some wrestling games. Though some of the move lists are kinda off (i.e. Stephanie McMahon & Trish Stratus) the create-a-wrestler mode makes up for it. Also the match types allow for numerous matches and the create a pay-per-view feature is a nice touch. Overall, even though today we have Here Comes the Pain, in my opinion, No Mercy is still the greatest wrestling game of all time.