I would love it if you could implement the Unlimited 150 format. :)

http://www.sixprizes.com/2012/06/07/150-introduction-unlimited-150/
http://pokemon150.webs.com/basicrules.htm
http://pokemon150.webs.com/advancederratabans.htm

Unlimited 150 is a fan-made custom format that attempts to make the Unlimited format balanced. The basic rules are as follows:

*Players use a 100 card deck.

*Players can only use 1 copy of each card (e.g. only 1 Hypnotoxic Laser); players can use 4 of each Pokemon, but only 1 of each version (e.g. only 1 Base Set Bulbasaur, 1 Expedition Bulbasaur, etc.). Players can still use infinite Basic Energy.

*Players start by drawing 15 cards, choose 8 of those cards to be your Prizes, then start with the remaining 7. Cannot play Trainers going first.

*Basic Pokemon with 150 or more HP are banned. (There used to be a ban on all BW-on EXs, but it was changed to allow cards like Mew EX.) Fully evolved cards printed in sets as Pokémon Prime and B&W series holo rares (striped foil) also count as Pokémon ex (in every way, even the name changes).

*Exact names are no longer a requirement for evolution (e.g. Erika's Oddish can evolve into Dark Gloom and then Vileplume). The exception to this rule is SP Pokemon (Japanese VS Pokemon are also treated as SP).

These are just the basic rules, there are more. The third link I provided has a small ban list (Sableye Dark Explorers is banned for example), and there are exceptions to limits for cards like Mysterious Fossil and Plasma Energy.

Thank you for your consideration.