I'm pretty sure that Nunnally was left as the leader of Britannia, well if that even counts as being leader of Britannia but you get the idea. By that point she was the only logical successor.
Suzaku is pretty much doomed to play the role of the guy supervising world peace, that's pretty much his role and you can kinda see if you watch the R2 picture dramas how he acts that way. He's stuck as Zero and it's pretty much done that way, but no revolutionary speeches and such like Lelouch did.
And C.C. seemed to be talking kinda like how you talk to a dead person when you're reminiscing. Like some people say that they believe Lelouch survived but it makes no sense to me. It really ruins the spirit of the ending and Lelouch's sacrifice, not to mention C.C. was alive so it couldn't be that way.
And yeah Lelouch was a good guy in my eyes, though not the conventional one. He went through pretty crazy methods and was no lawful good moralist, but you could tell by seeing him through the whole series that, at heart, he was a good guy. He always cared about his friends and whenever someone close to him was hurt/killed, he always felt it was his fault and his incompetence when it could not have been helped. The difference between him and Light is that Light acts like he cares about people and doesn't, while Lelouch acts like he doesn't when he really does.
And Geass's ending is my personal all-time favorite ending. Just the way Lelouch brings about the miracle and how he changes the world through his sacrifice was amazing. I loved Lelouch's character already but the last episode sealed the deal. Lelouch is now my favorite character of all time.