Persian being the best
Then liepard
after that Delcatty
then purugly
persion:Like Meowth, shoot for Timid, but avoid Hasty, if you want to focus on Speed. If you want to bolster Defense, go with Relaxed.
Delcatty doesn’t learn any moves. Wait to evolve a Skitty with a Moon Stone until it has learned Double Edge at level 42. Then, hopefully have a Delcatty with Double Edge, Faint Attack, Sing, and Wake-up Slap.
Worst Stat(s): Defense and Sp. Def
Recommended Nature: Adamant. Most of the attack moves Purrloin can learn will rely on the Attack stat, rather than the Sp. Atk stat. If you’re planning on using TMs to teach special attacks, then go with Naughty and let the Sp. Def take the hit.
Liepard
Type: Dark
Best Stat(s): Speed
Worst Stat(s): Defense and Sp. Def
Recommended Nature: Adamant or Naughty
Best Learned Moves: Night Slash, Sucker Punch, Slash, and Assurance
Source http://www.technologytell.com/gaming/119757/know-your-cat-pokemon/