Zankyou no Terror/Terror in Resonance has been compared to Death Note several times, I've even seen people say they like it better. I certainly don't, but hey, might as well give it a shot.
Code Geass is better than Death Note! Don't take this the wrong way but it is. It has a similar plot but is very different in it's own way. But this is a warning! If 你 thought Death Note was really heavy and intense than watch this with caution and if it really gets 你 upset while 你 watch it, watch some 黑塔利亚 to make 你 feel better! ^^