For me it's impossible to point out only one character from the movie, that I could call my favourite.
I like Hazel, for the same reasons that Adam likes him. Hazel is trully a good leader: knows what he needs to do; thinks of thelong-term future; treats every member of group with respect, etc.
I like Bigwig. He is really brave rabbit, isn't he? Remember how cooly he acted during road/hrududu scene?

I like Fiver and his relationship with his brother, Hazel. You can see in the movie how much they care for each other, like in the scene when Fiver went to look for Hazel.
To be honest, every character in the movie has some feature, thanks to which I can like them (at least a little). Even those on the bad side.