WARNING spoilers ahead if you haven't seen the series you shouldn't be reading this. if you don't care then please read on.
This series is pretty solid until we get into the second season in which we see a couple of story holes. I thoroughly enjoy this series and it's one of my favorites but I have to be honest the second season leaves something to be desired, at least for me. Let's start with the first season though we have a great build up to the ultimate ending of Lelouche's Geass going out of control as he talks with Euphy, and gives the order to kill the Japanese people. This causes the Japanese people to rise up an want to fight, ultimately leaving the battle to pursue Nunally and confront Suzaku at the end of the first season. The introduction of our main characters is great, you relate to them as Lelouche and Suzaku are standing around in the beginning of the series where he makes the vow to destroy Britania. When we find out that his mother has died, and according to Lelouche, he thinks that it was a inside job because he knows there was no way the terroist could have made it into the palace, we find out later on he is right and it helps us relate to the emotional turmoil he feels. You really find yourself rooting for Lelouch even though through out the series Lelouche hurts multiple people around him including the one he loves. There is, of course, the flip side to this..... you may find yourself identifying with Suzaku through the series as he is the white Knight. Ultimately, this series is about Lelouche as he destroys and rebuilds the world. If you're watching it in english it really isn't that bad but it's no where near the voice acting of the Japanese cast. Ultimately this show is about cool robot fights and supposed bad-ass tactics brought to you by the very intelligent main character.