Transformers: Armada Omnibus

This series is really interesting, as it allows writer Simon Furman (who, for the uninitiated, is like the Proust of giant robot comics) to build Transformers up from the ground with relatively little outside influence. This volume features both Megatron and Optimus Prime coming to Earth to lead up their relevant factions after the events of the last TF volume. One of the great things about this comic was in how it treated the relative leaders - there was a great sense of danger and fear created in the characters when they learned that Megatron was coming to Earth, and likewise a sense of calm from Prime's involvement. Furman does a really great job of giving the characters individual personalities as well, which is something that's never really been done well with Transformers before.