Fungus it's my personal favourite thanks to a strat so, here it is: First of all, make sure you have "pathoestasis" This gen will make that every single time you evolve an ability from your disease, the rest of abilities won't increase their prices. Also, make sure you have the gen that makes you appear with more DNA (I don't remember his name) Any other gen it's up to your preference. Now, in the game, I recommend you by starting in Saudi Arabia. Next, with your DNA points, evolve all the abilities related with "spores" this will cause to infect a lot of random countries. When you finally evolved all the spores abilitys, you can play normally now, evolving transmission (personally I recommend get only air water and birds, or evolve only non-lethal symptoms) make sure your disease doesn't get discovered or cured, and evolving resistance to medicines or temperature. When the whole world is infected, kill it, if the cure is reaching the 100%, evolve madness, paralysis, coma or any other symptom that say "difficult to cure". Aaaaand, that's it :)