First up is a CGI video of G1 Devastator combining with flare to take in account real world physics of the characters, with real world look (i.e. mostly yellow) that can't fly. The second video is another CGI cartoon this time Prime vs. Megatron with a Generation 1 twist. The last video is Megatron doing a cereal commercial, related to the Prime cereal commercials.
Return of Optimus Prime
Megatron vs Cereal Commercial
The entire cereal commercial series can be found here.