Toonami
Toonami is a programming block on Cartoon Network that specializes in action cartoons. Toonami infrequently premiered numerous Transformers animated series during its first incarnation from 1997 to September of 2008. Initially hosted by Moltar of Space Ghost fame, the block is then hosted by TOM after 1999 (voiced by Steve Blum since 2000), with Peter Cullen (referred to by TOM as "The Big Guy") narrating commercials and other promotions. One of Toonami's most popular attributes is its original title sequences, crafted from clips and soundbytes of their respective shows and set to funky techno beats.
Toonami ended its original run in 2008. It has since been revived as a Saturday block as part of [adult swim], with Blum once again voicing TOM.
Transformers series
Beast Wars
Beast Wars was Toonami's first Transformers series, replacing The Real Adventures of Jonny Quest for a special week of premieres in 1998. The five episodes in question were "Code of Hero", "Transmutate", "The Agenda (Part 1)", "The Agenda (Part 2)" and "The Agenda (Part III)".
Promo: Moltar introduces Beast Wars as Rattrap sends Jonny Quest to a gruesome fate.
Armada
Toonami wouldn't see any Transformers action again until 2002, when it premiered Transformers Armada. The first three episodes were combined and advertised as a "movie", premiering on the "all new" Friday night block. Reruns were then aired Monday through Thursday, with a new episode each Friday.
The Unicron Trilogy would be plagued by Cartoon Network's rather indecipherable scheduling logic, oftentimes being moved off of the block and back onto it without any warning, making following the series a chore at best.
Promo: Original teaser trailer for the Armada premiere, narrated by Cullen. This promo happens to be far more exciting than the actual series.
Intro: Excited? Don't be.
Energon
Beginning in 2004, Toonami moved to Saturday nights from its original weekday afternoon format and issued one new Transformers Energon episode a week.
Intro: "We gotta stop fighting each other." *punches*
Cybertron
Transformers Cybertron would be Toonami's fourth Transformers series, premiering in 2005. In 2006, they cobbled several episodes together to create a TV special called "Primus Unleashed". In 2007, as a tie-in during the opening week of the live-action Transformers film, Toonami dedicated an entire night to a Cybertron marathon.
Intro: "These guys rock!"