Beast Wars (1996-1999)

Starring:

Maximals: Tigerbot, Cheetor, Dinobot, Optimus Primal,
Airazor, Rhinox, and Rattrap
(Photo taken from tfwiki.net)

Garry Chalk voicing Optimus Primal

Scott McNeil voicing Dinobot

Ian James Corlett voicing Cheetor

Richard Newman voicing Rhinox

David Kaye voicing Megatron

I'm not ashamed to admit that this was the transformers that I grew up on.  I only caught a few episodes of the original 1980s Transformers cartoon show, but I never missed an episode of Beast Wars.  

Based in the future, long after the end of the wars between Autobots and Decepticons, two factions of Transformers are now in a cold war-- the heroic Maximals and the treacherous Predacons.  The Maximals being a branch of Autobots, and the Predacons being a branch of Decepticons, naturally.

The original Optimus Prime and Megatron and their associated transformers are hardly featured at all in Beast Wars.  This series is connected to the characters we're familiar with, but these new descendant characters carry this show all on their own.

The Predacons, featuring both the initial Megatron in T-Rex Beast Mode
on the left, and his final Dragon Mode in top center.
(Photo taken from transformers.wikia.net)

In the future, the Maximals are on an exploration mission when they are attached by a Predacon warship.  The Maximals are lead by Optimus Primal (who named himself after the legendary Prime) and of course the Predacon warship is lead by Megatron who, similarly, chose his name after his own personal "hero".

In the battle between ships both are pulled into the wormhole that the Maximals were exploring, which transports them through time and space and crash-lands them on an ancient and mysterious planet.

The Maximal/Predacon war continues between these two small groups of transformers as both vie for a way off the planet, as well as a way to keep their future from being destroyed.

Dinobot: this Predacon turned hero Maximal had the most
character-depth of any other, and frequently quoted
Shakespeare, esp when facing a tough decision.
(Photo taken from unicron.us)

The storylines are original.  The characters have real depth and feeling.  The villains are threatening.

Overall I really enjoyed this show as a kid, and I recently rewatched every episode for nostalgia, but ended up enjoying it all over again as an adult.

Optimus Primal: "I will not give an order I would not be willing
to do myself!"  This declaration to his subordinate inspires me still.
(Photo taken from home.comcast.net)

Factoid: This computer-animated cartoon show won a Daytime Emmy in 1997 for Outstanding Individual Achievement in Animation.

Factoid: This show introduced the concept of transformers having a Spark; which was a sort of soul for transformers.  This concept has been continued in all Transformer TV shows since, as well as Michael Bay's movies.

Factoid: Optimus' Gorilla beast form and Megatron's Tyrannosaurus Rex beast form were chosen as homage to the classic fight in the movie King Kong.

Beast Wars: Transformers is currently available on Netflix.