[Roanstalker]

For the Brave line we got plenty of pics here already Masterpiece Great Exkaiser on the way:

http://www.toyark.com/brave-eldoran-thread-932/

The gist of it is that after Transformer's sales started to wane in japan Takara sought another line. This line is similar to Transformers in that they have transforming vehicles and/or beasts. The storylines for each series is independent of each other and are mostly different concepts alltogether.
But apart from Gaogaigar (the last series) all leader braves follow the concept set out by Ginrai and Victory Saber of smaller brave that combines with some/a vehicle(s) and later adding another big brave to the mix who may or may not already combiner with the smaller lead brave ut then also combines with the earlier vehicles to form a gargantuan brave.
Starting with Fighbird Support Braves also get an upgrade part way through the series.

I'll outline the basic concepts of each series.

Brave Exkaiser: Energy life forms comes to earth and possesses earth vehicles to combat spae pirates (4 of which are Dinobot remolds who never got toys and their leader is a whole new design that actually got produced).

Brave of The Sun Fighbird: Energy Life forms comes to earth again but their lead possesses a android so he can interact with the humans more so than the previous series. Their enemy is also a energy life form called Draias.

Brave of Legend Dagarn: Earthen spirits are awakened and possess earth vehicles to protect earth from invaders from space.

Brave Express Might Gaine: AI robots are made to combat crime syndicates.

Brave police J-Decker: Same as above.

Brave of Gold Doldran: Spirits from Power Stones are awakened.

Brave Command Dagwon: 6 humans are chosen to wield the power of Dagwon to combat escaped prisoners from the space prison Sargisso.

King of Braves Gaogaigar: A bit complicated. Zonder El-01 crashes into Gai's shuttle and nearly kills him. He is rebuilt as a cyborg and along with alien machine Galeon and earth Gao Machines combine together to form Gaogaigar. His supports are all AIs. All enemies in the first half are sent by El-01 but the second half of the series is a bit different. As I said earlier, Gaogaigar does not combine any further than Gaogaigar. But he has several weapons granted to him for added fire power. Most popular is the Goldion Hammer which is literally a giant hammer.

Gaogaigar Final: The 'end' to Gaogaigar. Features Gaofighgar (Different inner unit than Galeon) and Genesic Gaogaigar which is the 'original' Gaogaigar and the first and last Brave to be completely made out of animals and no vehicular influences (I discount Gaohn because he was made to go with Dagarn).