I also still have a small trilobite fossil, somewhere…
I also like dinosaurs. I even bought a fake Velociraptor head fossil from the Welcome Center in the Jurassic Park portion of Orlando’s Universal Studios. Again, it is somewhere… I am sure that there are a lot of dinosaurs out there that I do not know about, besides Gojirasaurus. Technically, since all birds are descendants from Dinosaurs, then my favorite “extant” Dinosaur (besides Alligators and Crocodiles) would the domesticated chicken - Gallus gallus domesticus. It is even funnier, since in real life, Velociraptors were the size of modern day chickens! 
But to get back to the original question, my favorite extinct organism would be Anomalocaris. I mean, when was the last time a giant shrimp was the apex predator of the ocean?
A depiction of Anomalocaris canadensis. Original image “Anomalocaris2019.jpg” by PaleoEquii from Wikimedia Commons, 2019, https://commons.wikimedia.org/wiki/File:Anomalocaris2019.jpg. Accessed 17 December 2020.
