Man, when i first saw Kovu, it was love at first sight.... Vitani running up close behind. But ya'll do have a point, although im probably going to go with more of the 'popular' ones, the lions. Although MANY bad things happened to preety much all of hte lions.....
Simba ~ He had to 'run away and never return'.
Mufasa ~ Well, he died for doing nothing.
Scar ~ Uhh, he died.
Sarabi ~ She lost her mate- and her son, thinking they were dead.
Sarafina ~ I really dont know.
Kopa ~ He went poof xD
Nala ~ She thought she had lost Simba
Zira ~ She died... again.
Nuka ~ He died.
Kovu ~ He was forced to kill the oes he loved.
Vitani ~ Once more, she was... err... i dunno
Kiara ~ She never got to do anything by herself.
Well, thats if you look at the bad side. If you look at the good side....
Simba ~ He became king.

Mufasa ~ He was a greta king when he was alive
Scar ~ Well, umm, he got to be king for a little bit
Sarabi ~ She was the queen of he Prife Lands.
Sarafina ~ Umm, she was never invloved with the bad stuff?
Kopa ~ He went poof. xD
Nala ~ She got to be with her true luff, Simba.
Zira ~ She had this big plot to take over the PrideLands... she was happy then.
Nuka ~ When he was the only cub.
Kovu ~ In the end, he got to be with Kiara.
Vitani ~ She got to be a PrideLander
Kiara ~ Same as Kovu.
As for Shenzi, Bonzai, and Ed, they never really had a big part in the movie, never had enough to time to get to knwo them. If I did know more about them, they might of just creeped up to the front of my list.