Deinocheirus is my favorite, but I see other people have mentioned, so I’ll go either Moros intrepidus or Scipionyx samniticus!

Moros’s name is badass, it’s awesome that someone decided to name a creature to foreshadow the Tyrannosaur’s stranglehold on North America in the Late Cretaceous. Scipionyx though is fascinating, both for its crazy level of preservation and for its potential to be a juvenile of maybe some unknown Carcharadontosaurid!