I'm a fan.
I posted the question because I scored pretty great, almost-free tickets to Puccini's Madame Butterfly last Friday at the Lyric (which was directed/staged phenomenally), and it'd been several years since I'd seen anything operatic on the stage. Nice to see more, and more interesting, responses than I anticipated.
Opera's interesting because it prioritizes spectacle while often de-emphasizing story (and it does help to review an opera's main narrative in advance if one isn't already familiar). In a lot of ways, I think its akin to our contemporary comic-book-based films, except the spectacular in opera is much more musical and much less visual.