I know a lot of people are upset with how it ended but I've come to expect shock value and cliff hangers from Code Geass. As someone else has said the show is not really over so I just feel episode 25 was another episode in the whole scheme of things and not an ending at all.

And I think ending the show with both Lelouch and Suzaku (and Karen) aware who the other was with guns pointing at each other was the perfect way to end the first season. It just made me anticipate the next season even more. My only complaint is I wish Sunrise would have told us when the second season was starting.