Well, the official on-line
Code Geass Character Popularity Poll intermediate rankings so far (as of 2006/11/19) are as follows:
1. Lelouch
2. Karen
3. Suzaku
4th was C.C and 5th was Jeremiah (orange power ftw). Since these initial results C.C has apparently now dropped down to 5th (negative feedback to product placement?), but it doesn't say who is now 4th. lol
Source:
Code Geass official blog