Hmm, the only game that gives me some challenge might be Supreme Commander too. Gives the AI lots of resources and a bit of time, and you'll see lots of things shooting at you

With AI, it still depends on you. If you're a master strategist, even on extreme -ing hard, it will still feel like a breeze to you

With human, heheheh . You can never find an opponent more mischievous, lying *******, double stabber than the person playing next to you O_o Oh, so much fun