GeckoLib comes packaged with an examplemod. It is not built in the final jar, but you can run it and mess with it by cloning the geckolib repo and running it like a normal mod.
GeckoLib has two example entities, a bat that uses molang for all it's animations, and a bike that showcases some more advanced molang queries. This section will be updated with more complex entities soon.
GeckoLib has the botarium and fertilizer example block models. The botarium simply opens up over and over again and the fertilizer switches models, textures, and animations based on the current rain state. Again, this section will be updated soon.
JackInTheBoxItem is the most detailed and well-commented example so far. Make sure you take a look at it, it serves as a good example. The item plays music and an animation on right click.
PotatoArmorItem is the second most detailed example. It plays the armor animation only when all 4 armor pieces are put on.
The only replaced entity example is the
ReplacedCreeperEntity, which is self-explanatory.