Here's the best one
EPISODE 41: CYBERTRON ON THE MENU, PART 1 (two-part series finale)

Still mourning the loss of their leader, OPTIMUS PRIME, the AUTOBOTS are called back to CYBERTRON to face the biggest TRANSFORMER of all--a monster that threatens to eat their home planet whole!

EPISODE 42: CYBERTRON ON THE MENU, PART 2 (two-part series finale)

With OPTIMUS PRIME out of commission, will BUMBLEBEE have the power to open the ALLSPARK and defeat the TRANSFORMERS' largest enemy ever, while simultaneously giving all the AUTOBOTS and DECEPTICONS even more cool new paint jobs? Also, OPTIMUS PRIME returns, but will he be good or evil? Also, why are plants growing on CYBERTRON? Also, what will MEGATRON find on the ORIGINAL GENERATION ONE AUTOBOT ARK and what are the VOK and who is WHEELIE and why does he die? Also, the ALLSPARK KEY is damaged, and SARI uses the ALLSPARK KEY to repair the ALLSPARK KEY so she can use the ALLSPARK KEY to repair AUTOBOTS damaged by the ALLSPARK KEY at her birthday party! Don't miss a second of this thunderous two-part SERIES FINALE!

Biggest Transformer of all? You know what it is     YAYAYAYAYAY!!!! XD