Madara was a better brother. Sasuke didn't want to respect Itachi's wishes. Madara was a real nicca and honor'd his brother, or at least he actually tried. Tobirama had to scare Sasuke into fighting for Konoha.
After losing several brothers to clan warfare, he had a self-obligation to protect Izuna and was even dedicated enough to continue fighting in his brother's honor.
Though I'm not saying Sasuke is a bad brother, I'm saying I'd put Madara over Sasuke in this field.
Madara. Sasuke went against itachi's wishes and tried to destroy the village. That is an immense insult to a brother who deeply loved him and sacrificed a lot for him. Sasuke let his revenge consume him too much.