Isn't Mifare in different forms a de-facto standard for NFC subway tickets around the world? St Petersburg uses Mifare Classic (and tokens), Moscow also uses Mifare Classic for the refillable Troika card and Mifare Ultralight for disposable ones, Dubai "nol" card is a Mifare Desfire, Los Angeles "tap" card is a Mifare Classic, and, yes, the London Oyster is a Mifare Desfire EV1. Yes I actually went through my stack of transit cards and scanned those of them that I wasn't sure about.
The only ones that I came across that are not Mifare, and not even readable by Android (but readable by the Flipper Zero), are the paper tickets used in Brussels. Then, of course, there are non-NFC tickets. For example those that use magnetic stripes, like the cute tiny ones in Paris or NYC's MetroCard.
There are two distinct types of Oyster card, but I don't know which is which, other than from a user perspective. All I know is that I had an old style one (the one without the white D in a blue square on the back) and you could still use it, you just couldn't "connect it" to the app so you couldn't look up your travel history.
There was a complicated process for returning it and getting a replacement, but as they'd already phased in paying by bank card by then, and the only advantage of an oyster card was for season tickets, I just returned it and got my deposit back.
But if you're into collecting different card types, you might want to try to get hold of one of these old ones as well. They're probably somewhat rare now, as they were encouraging people to upgrade to the new ones at least 5 years ago.
Japan uses FeliCa for its integrated transport cards (I just read an Osaka Metro ICOCA card with NFC Tools to check). This is used by quite a few systems around the world, including Hong Kong's Octopus.
That's a lot more MIFARE Classic than I would have expected considering that reader support for those is a lot less guaranteed these days. I guess a lot of them might be legacy systems.
The only ones that I came across that are not Mifare, and not even readable by Android (but readable by the Flipper Zero), are the paper tickets used in Brussels. Then, of course, there are non-NFC tickets. For example those that use magnetic stripes, like the cute tiny ones in Paris or NYC's MetroCard.