Thank you.
They both complain a lot, but there is one important difference. Lelouch is proactive. He builds the Black Knights from the bottom up and tries to destroy the most powerful nation on Earth. When he complained I never got annoyed because I knew he would try to do something about whatever injustice he felt had been perpetrated.
Shinji on the other hand is so incredibly passive. He has every situation, even the ending, forced on him. He never does anything but react or in some cases have a mental breakdown and
fail to react to the world around him. I disliked Shinji the first time I saw Eva, but the second time through I really tried to empathize with the character and I enjoyed the whole show on another level.
There are similarities, but I think there are also some serious differences in the characterizations of those two. I will, however, admit to being biased. I love Lelouch for being such a
Large Ham.