I actually prefer the opera, but I also like operettas a lot (you know, the predecessors of musicals, something between opera and musical ... but it has more class than most musicals do

.... I hate Andrew Lloyd Webber's stuff, except for his awesome Requiem ... err, back to operettas) :

The Bat
Madamme Butterfly
Countess Mariza
Land of Smiles
The Merry Widow
Orpheus in the Underworld
etc.

(I don't know the English titles of most other operettas, sorry...)

Oh, and as for musicals:
The Bitter Suite (that's the Xena musical, and it rocked !!!)

Doc