Surprised there's a resounding vote for Aladdin, when I would definitely recommend Les Mis. I think if you've seen past Disney musical productions and enjoyed them, then go for it. Personally, I found it too childish and the music, singing, and acting was mediocre. Costuming was overwhelming in a bad way, and blocking was atrocious, it just seemed like the stage was a blobby mess of people. And stage design was ugly and kiddish. JMI was great but he alone could not save it for me as the material overall was very bland. I love classic animated Disney movies but have been underwhelmed by them on the stage.
I love Les Mis for its incredible orchestration and music and the story has such emotional depth, with a decent amount of comic relief. The cast seems to be getting better since the revival's inception. I recommended Les Mis to a friend and she and her boyfriend fell in love with it. They ended up watching the whole 10th anniversary special because they couldn't get enough of it. Then saw it live again.
So it really depends on what your preferences are. What other shows are you catching?