Earth
The planet we're on. Was destroyed in at least two timelines.
Big Bad Timeline
In Member OG, the Western Hemisphere was destroyed by Lupus's laser that was supposed to destroy the entire world after SwordMaster accidentally activated it (when only half the world was destroyed, Lupus mused his regret at having traded its Contractor Core for an EXP Egg). But it got better, actually I think it was only restored in the non-canon Member OG 5s as well as the last Christmas Member OG post which I don't count anyways as a way of making the status quo easier to understand for newcomers. But then in Member OG 5: Secret of the Ooze, Akujin used an X-Bomb to blow up Earth so that he could search the rubble for the four stones that sealed away the Writer's Chair. He was unable to complete this task, as the OG Six kept him busy on Krad, and Earth (Western Hemisphere included) was restored when BSD made a wish to the Holy Plot Device (reverb). Most were unaware that the planet had even been destroyed.
Control of the planet was largely split between Team Rocket Omega in the Western Hemisphere and TWIFATIT in the Eastern Hemisphere. In Member OG 8: This Title is irrelevant, the Earth was squished flat when Lupus used the Limitless Drive to collapse the three dimensions. It was restored in Member OG 10: Full Circle. Following Lupus's death and the subsequent collapse of his organization, the governments of Japan, Canada, Italy, Portugal, Venezuela, and the New Oceanic Republic joined forces as the United Super State Region (USSR). They formed a peacekeeping team with the help of refugee Kradians to retake the planet from TRO and other evil forces, but were probably collapsed when Lupus was resurrected and brought TWIFATIT back with him.
In The OGers: The Third Generation, TRO collapses when the OGers destroy their main headquarters and Magikoopa gives up his position. In the wake of their fall, TWIFATIT begins to claim their territory.
Good Ol' Timeline
The world remained hunky dory, though in Gamehiker Member OG 2 it was nearly taken over by an Ushutarian invasion. In the year 2065, the Earth was seemingly destroyed when the Ushutarians returned, but it was instead swapped with a decoy (Anti-Space Earth) while the real Earth was hidden inside of Anti-Space. The survivors established colonies in the Sol System while making Mars the base for human population.
Other Lands
The setting of the Pikmin OG. According to Greg: "Plot twist. It was Earth all along!"