haha, this is a question that forces only oppinionated answers, but ey im down.
Definately true OG kush lines are the top in my opinion,
Easiest? idk but marijuna-seeds.nl's Autoberry did very well for me, it was basically plant seed water, then feed when od enough and wait; 52 days later voila! Although I've READ that LOWRYDER's are pretty durable and easy.
Strong THC? hmmmm, Hash Plant.
as stated before you cant go wrong with the cheese strains.
Wiz khalifa even said it's his fav.