I ran across this Top Ten List on Opera America's website that set me to thinking about top ten lists, and I did a little searching. The Opera America list is their Ten Most Frequently Performed Operas in alphabetical order. The source of data or inclusive dates is not given, but it is a believable list and the only surprise to me is Hansel and Gretel, an opera often produced at Christmas time for children. Opera Pulse has a website that maintains statistics on opera performances. If we look at the data for 2014-2015 season from the Opera Pulse database for the operas most frequently produced in that period, we must remove Aida, Cinderella, and Hansel and Gretel from the Opera America list and add Tosca, Rigoletto, and Don Giovanni. However, we can't fault Opera America too much; the three deletions from their list are nos. 12, 27, and 16 on the Opera Pulse list; note that means that Hansel and Gretel is still in the top twenty.
Aida The Barber of Seville
The Barber of Seville La Boheme
La Boheme Carmen
Carmen Don Giovanni
Cinderella Madama Butterfly
Hansel and Gretel The Magic Flute
Madama Butterfly The Marriage of Figaro
The Magic Flute Rigoletto
The Marriage of Figaro La Traviata
La Traviata Tosca
How many have you seen? Well, starting in August you can add FIVE operas to your ‘seen in person list’ over the 2016-2017 season: La Boheme (Wolf Trap Opera), The Barber of Seville (Virginia Opera), The Marriage of Figaro and Madame Butterfly (Washington National Opera), and La Traviata (Pittsburgh Opera). These companies are also offering other members of the classic repertoire as well as newer operas; see the Seasonal Listings page.
One might also ask how do the lists of most performed operas compare with the ten “best” operas lists sometimes seen. These are lists compiled by critics and other writers about opera. However, this is where it gets…shall we say complicated. It depends a lot on who has compiled the list, usually one writer or one critic, and often they make a number of caveats or qualifying statements about the list, and sometimes, it is really just a most popular list. Forthwith, let’s take a look at a Best Operas of All Time list on the website, Ranker.com. It turns out that the ranking is determined by audience votes, making it more likely a popularity contest.
Gramaphone, a well-known classical music review site published their Ten of the Best Operas list, which they termed “a newcomer’s starter pack,” and it's worth a look; they are trying to give you a broad view of opera. In addition to operas already mentioned above, they included Fidelio, Tristan and Isolde, and The Cunning Little Vixen, and helpfully, also specified the specific recordings to listen to. First I have heard of Janecek’s The Cunning Little Vixen; got to check that one out.
The Guardian, another trusted website is unable to stop at ten and lists the Top Fifty Operas, which is a good list to help focus your attention on consensus repertoire members. I am not familiar with his website, but The Imaginative Conservative lists the Top Ten Greatest Operas; it is a somewhat different list, but to the author’s credit Nixon is not on the list and there are several we can agree on. For liberals, NPR (hey, that’s what conservatives say) has taken a stab with our longest title list, 10 Operas You Need to Know from the World of Opera. Additions not previously mentioned include Pelleas and Melisande, Wozzeck, Eugene Onegin (one of my favorites), and Werther; audio samples are offered from each opera. Their list also includes Janacek's The Cunning Little Vixen.
It’s interesting that the “classic repertoire” of operas that get repeated over and over is largely a recent development. Until the mid 1800s, operas were produced and offered a few times, maybe then moved on to opera houses elsewhere. But mainly, they played a run and were soon replaced by a new offering, sort of like movies currently are. It is only recently that new operas have slowed in coming and opera as an enterprise has moved to largely repeating classics. I think I am seeing a move to more new operas. We'll see.
You can find other lists on the internet or in books. There is a lot of overlap, but each may have a few favorites of their own. However, make sure you check the basis for the selections to understand where the list comes from. You can start your own list, which is after all the most important one, and living in the mid-Atlantic region of the U.S., you will have lots of opportunities to add to it .