Do you mean stage musicals or movie musicals? I am in no way a super good judge of a musical, I tend to be very easily pleased by them. I sing a lot in my daily life, by myself or in public, trying my hardest to make my life a musical but so far very few people have ever joined in.
Movies: Funny Girl, Enchanted, Sound of Music, Chicago, Moulin Rouge, Fiddler on the Roof, Dancer In the Dark, The Muppets, Hello Dolly
Stage: Wicked, Hairspray, Les Miserables, Matilda the Musical (new favorite!), Next to Normal, Sunday In the Park with George (which you can get a recording of on DVD and I highly recommend)
I dunno, I just love musicals. It takes a lot for me to dislike a musical. Even ones I know are dumb (like Mamma Mia and High School Musical) I still have a lot of fun watching because it’s just fun to watch people break out into song and choreographed dance. :)