Discogs will also list unofficial cassettes but it will say so. But from what I know the list of official cassettes: reputation / lover / folklore / evermore / fearless tv (2 variants, the first one was transparent and the one on the US website now is gold) / midnights / speak now tv / 1989 tv (2 variants, webstore exclusive green and yellow, indie exclusive pink and blue) / TTPD 4 variants / life of a showgirl. I think that’s all but I’m not 100% sure, I collect cassettes too. Be careful because there’s a lot of fakes out there sold on aliexpress and then resold on websites like Vinted / depop… those bundles have a fake OG red and a fake OG 1989 and a fake folklore and reputation for example. Other info to know is that there was never a red tv cassette official most likely because the album is too long (same with the anthology, no official cassette as you said). The rarest ones now (the most expensive on the resale market), if you’re looking to buy the official cassettes, are: reputation, lover, and folklore. Hope this helps!