I also like both.
Before, I used to like Lakshman because I did not know much about Balram and the character of Lakshman was always more darling and beloved to me, he was truly the ideal younger brother. But recently I have begun to know more about Balram and I have grown to love and respect him too.
Yes, he did like Duryodhan, but why should that be a wrong thing? Balram was an impartial teacher and he valued skill above all else. He liked the student who had more skill and was more dedicated to his studies, and that was Duryodhan. But because he would never support evil over good, and yet he could never verse his favorite student, he remained neutral in the war. Balram always supported Krishna and even though he was Krishna's elder brother, he respected him like Lakshman respected Ram.
So yeah, I cannot choose.😃 To me, while Ram and Krishna were different in personalities in their avatars, Balram and Lakshman remained the same. Both were dedicated, served the Lord throughout their life, and always become righteously angry whenever the Lord was insulted by others.