I will vote for Trump coin launch. When the coin shattered after 2-3 days, most of the trust on altcoins was lost among millions of crypto users. The scar is not going to go away easily.
I think the biggest is the one by Argentina president and Kelsier ventures because after it was rugged, it really served as a wakeup call to everyone in the crypto community about how much damage bad actors can make if they get more control over a network, community or chain.
If you're going to mention trump, just say the Melania launch because Trump's own isn't half as bad.