Code Geass. Even though both 2nd halves were a trainwreck compared to the first halves. I still enjoyed code geass more. Code geass's ending is also probably my favourite ending ever!
Death Note, definitely. More edge-of-your-seat thrills, better leads, animation, music, and a more satisfying conclusion (Light actually deserved to die).
Death Note takes this. Cooler looking characters. More original story. Thrilling series without a single real fight. Amazing ending that shows you how low people who think of them as divine really are.
Code Geass takes this. Cooler looking characters. More original story. Thrilling series that doesn't rely on fights. Amazing ending that shows you how a true hero should be.