I'm by no means the greatest GM, but my friends seem to somewhat enjoy it. Below are some of the campaigns and one/two/three/four-shots I've previously ran.
A four-session campaign. The first three sessions were run over the course if a few months, while the final session was ran over a year later. Ran using Dungeons & Dragons Fifth Edition, specifically the rules contained within the 2019 Essentials Kit (though some character options were taken from ither publications).
The campaign centred around the small home-brewed village of Hogsdeep, founded by Hagelthum Hogrider, a swashbuckling adventurer who made his fortune during the Great War, 200 years before. Palax, a dragon with a long memory, sought to take his revenge on the legacy of Hagelthum, in retribution for the Hogrider's thievery from his lair.
The adventure concluded with the dragon's fiery attack of the town. The players successfully rallied the townsfolk to their own defence against the dragon's minions, though not before Townmaster Hallwind Sunholm perished in the flames. The dragon was eventually put down by a brave adventurer, flung up into the sky by a ballista, grappled the dragon, and drove their sword into it's cranium.
This 3-session game started as a one-shot for a bunch of new players. The game was ran using the Fate Condensed system, and was set in a homebrewed setting that I roughly described as 'Fantasy 1815'. The geography was non-descript, and was not designed to mirror any real-world location, but the level of technology jn the world was broadly in-line with what was available in Napoleonic Europe. Dwarves still lived in the mountains, Elves in the forests, and no doubt Halflings/Hobbits were around as well, but for the past 200-300 years, muskets had been common, and technology had once again become stagnated, as tends to inexplicably happen in fantasy settings.
The original one-shot centred on a group of adventurer/mercenaries, who had taken a job to trek into the far North, to the settlment of Wyvern's Pit, to track down a treasure, a magical crown, that had recently been reclaimed from a local dwarven fortress, and subsequently disappeared.
Following a successful recovery, the criwn was discovered in a broken state. Session 2 lead the adventurers into the previously mentioned Dwarven Fortress, in an attempt to find a way to repair the crown, and see what further treasures still awaited them. It was here that the players awoke a spectre, who chased them out of the Fortress, but not before they received a vision of trouble back in their home city of Northgate
In the final session, the adventurers returned to Northgate, uncovering a magical war that was on the cusp of breaking out between various clandestine wizarding factions across the world. The adventurer's managed to defeat one of the wizarding factions within the city, before discovering that another, tied to one of the character's backstories, had fled. They were requested to meet these wizards in another city.
I did have some rough plans to extend this into a full-blown campaign, following the wizards war as various factions, both mundane and magical, vied for power. I may return to this one day, but I also had many ither systems I was keen to trial, and so this has been on pause ever since.
This campaign followed the Lost Mine of Phandelver adventure detailed in the D&D Fifth Edition Starter Set from 2014, and was ran using the D&D Fifth Edition Players Handbook. It was set in Faerun's Sword Coast, from the Forgotten Realms setting, but as I was also interested in the Greyhawk setting at the time, I declared that the continent of Oerik was across the sea. In the end, this jad no bearing on the plot
The campaign lasted around 15 sessions, and took the Player Characters from 1st to 5th Level. I also included some details from the later 2019 Dragon of Icespire Peak adventure from the D&D Essentials Kit.
This was my second attempt running the campaign. I had previously attenpted to run tue campaign about a year or so beforehand, but the group was eventually defeated by scheduling. I did toy with running the second attempt as an in-universe sequel to the failed campaign, but I decided that would be slightly too much effort for very little pay-off.