The first season was brilliant and one of the most enjoyable things I have ever watched. The second season felt a bit rocky, though, it was still very much enjoyable. While I will not deny the flaws of this show, it's brightly shining magnificence outweighs that.
I would absolutely recommend this anime to any fan of action, mecha, and brain over brawn. For so much of the series, the question of "Lelouch/Zero or Light/Kira" constantly weighed on my mind due to their similarities and brilliance.
[SPOILERS]
There were some parts that were hard to sit through and just plain boring to watch, but the rest made it so very difficult to look away. The ending of the anime was so unexpected that, despite knowing that Lelouch would die and that he purposely made himself the world's most hated man, I as still so caught off guard. I applaud yet another unexpected miracle performance by the hands of Zero.