Religions

Gen 1 & 2
During the Gen 1 playthrough, many religions formed to explain many of the events that occured in-game. Most religions associated with one of the fossils that can be acquired in game. Even amongst the three major religions, divisions formed surrounding certain events and characters such as The False Prophet and Bloody Sunday.

Although the religions have seen dwindling followings in subsequent generations, core groups still follow the religions. Some have even stated that the event of Gen 3.5 (Randomized FireRed) was a victory for the Dome Fossil and that Gen 4 (Pokemon Platinum) was a victory for Helix Fossil because of it's all anarchy run.

Major Religions
Church of Helix

Disciples of Dome

Followers of Old Amber

Pantheon

Other Religions
Old Cults of the PC

Gen 2 didn't really introduce any new religions (besides the Johto Heathens, whose goal was to tear down the religions of Gen 1) but instead mainly expanded on what was introduced in Gen 1.

Gen 3
With the new chat to speak function being implemented on the main stream people clung to the fossil gods of Root and Claw. They believed that Root was the cause of the speaking voices and the voices gave potato to Lord Root as an offering. Claw on the other hand was deemed the cause of the silence when the voices could not speak to themselves, he received only praise by the voices that were annoyed by the noise. So, Claw and Root joined the pantheon as the gods of silence and speaking.

Teachy TV
(?? religion?)

Trolls
While this group has always existed, they came into full prominence during Gen 4 prior to which their impact on the stream was minimal. But with the advent of the touch screen, a group of players who want nothing more then to derail the stream cause controversy and release beloved Pokemon more easily.

Team Plasma (voices)
A group of TPP players who have taken to the teachings of Team Plasma. Their goal is to release Pokemon and generate PC shuffles. Unlike trolls, their goal is not to disrupt the stream and will even actively help the game progress and act like normal players when not near a PC. As a result of this, they can be hard to identify. The group as a whole has veering goals with some wanting a full release of everyone and others only wanting to release certain 'mons. They also appear to be more organized then the trolls.

Laironism
People in Twitch Plays Pokémon chat started spamming "Lairon is the new lord helix." It took a while for people to get hyped about the new God, but many people started dissing Lord Helix himself to the point where extreme Helix believers requested a battle in which Arceus, Pidgeot, and Omastar would duel Aron, Lairon, and Aggron. Hardcore Helix fans made the Steel/Rock type trio only use status against the lead of the other team, Omanyte.