I set up a ladder for Pokemon Diamond and Pearl for the hell of it. Keeping track of wins/losses and even tournaments (when I figure it out). It's as simple as challenging someone to a match and the loser reporting their loss on the ladder from the link on the menu. That way you can see who's the best of the best here, and maybe eventually from around the world!
The rules I decided on in general are:
# The Uber Pokemon
Uber Pokemon are considered to be overpowered in comparison to the rest of the Pokemon in the game and as such, players may not have more than one uber Pokemon on their team. The uber Pokemon are considered to be Mewtwo, Mew, Wobuffet, Lugia, Ho-oh, Latios, Latias, Kyogre, Groudon, Rayquaza, Deoxys, Palkia, Dialga, Giratina, and Manaphy as well as Darkrai and Arceus. Darkrai and Arceus, however, are not currently available to players outside of Japan.
# Sleep Clause
Unless the effect is caused by Effect Spore or Rest, players may not induce sleep upon the opponent if another of his or her Pokemon already has the sleep status.
# Species Clause
Players may not have more than one of the same species of Pokemon on their team. For example, a team of six Blissey would be ridiculous.
# Honesty
Players may not use Pokemon obtained from cheat devices or glitches in the game. Players should try to be considerate of each other and play fairly to make the game as fun as possible for everyone. Lying about winning or losing a match is strictly prohibited as well.
and about Disconnecting...
Disconnecting from Nintendo Wi-Fi or moving out of range to end the battle is dishonest and will not fly here. Legitimate technical issues, however, can't be helped.
Coming up with additional rules before the match and aggreeing upon them is cool too. But these rules above would remain in effect, unless there is a better suggestion from anyone?
http://www.myleague.com/sinnohleague/