Some references from the films: When R2 was dismembered on the operation table reminded one of the Vader armor scene from Revenge Of The Sith. Also Grievous vs Ahsoka combined elements from the Luke versus Vader duels from Empire and Jedi.
As Thundercracker pointed out, Grievous is fucking awesome in the series. The next episode Bombad Jedi is a one-off by Troop's Kevin Rubio and should be viewed as such. Haters will use it rage against Lucas but the episode should be viewed for what it is: a comedy episode.