000SUPERGUY is the main universe of the Superguy imprint. It's a world not unlike the Looniverse, except that it's based less on specific comics parody and more on general superhero parody, with more parodies of Real Life figures. It has its own heroes, such as Andy Awesome, Ramrod, Team Cynical and the Adjusted League Unimpeachable (its greatest hero, the titular Superguy, never actually appears on screen), and its own ridiculously complex history. Luckily, there are only a few stories and characters LNH readers really need to concern themselves with.
In Chris Meadows and Dave Van Domelen's Grand Tour, DeFacto V recruited allies from 000SUPERGUY as part of his plan to regain control of his original timeline. He sent the Mighty Muddy Power Grangers, enemies of Team M.E.C.H.A., to the Looniverse to fight Dvandom Force. Team M.E.C.H.A. traveled across several universes to find them, and joined together with Dvandom Force for a final climactic battle. Stranger Tales #7 detailed what would have happened if the two worlds had been amalgamated, as with Marvel and DC's Amalgam event. At the end of the crossover, Errand Boy crossed over to 000SUPERGUY and became stuck there.
In Mike Escutia's Auld Acquaintances, the baby Father Times of the Looniverse and 000SUPERGUY for the year 1996 were accidentally switched, with the LNH's Neon Lad and Search Lass and Starwave and Soundbyte of Superguy's Hero Patrol being recruited to rescue them from car thieves. In Stolen Hearts, Search Lass was kidnapped and whisked off through the altiverses, with Neon Lad and Reverb Boy in hot pursuit.
After another Escutia character, the Master of the Net, was defeated in the Looniverse, he moved to 000SUPERGUY to continue his plans there; at one point, he came into conflict with none other than Team M.E.C.H.A.
During Beige Midnight, Superguy himself traveled to the Looniverse to deal with a horde of villains while the LNH was otherwise occupied. Typically, he was never seen, and the LNH learned of his visit from a note he left behind.
During the Spoon of Destiny Saga, some of the Lemurs who came to 000SUPERGUY from alt.fan.lemurs fled because of Superguy's steep drop in activity, traveling to the Looniverse. After passing through the LNHQ and creating all manner of chaos, they traveled through a dimensional portal to Earth-20.
000SUPERGUY is part of its own expansive multiverse (much of which was explored in Mike Escutia's Hero Patrol). For more than you could possibly want to know about the Superguy altiversal structure, read the FAQ.