Sure. One great Gravity Falls crossover fanfic is 'Gravity Falls and Steven Universe: Crystal Falls'. It combines the mystery of Gravity Falls with the magic of Steven Universe in a really interesting way. The characters interact in a believable manner and the plot is engaging.
Another one to check out is 'Gravity Falls / Adventure Time: The Land of Ooo and Falls'. It mixes the strange and wonderful worlds of Adventure Time and Gravity Falls. The art styles blend well in the fanfic, and it creates a unique story where Finn and Jake meet Dipper and Mabel, and they all have to solve a mystery that spans both their worlds.
One great undertale gravity falls crossover fanfic is 'Falls into the Underground'. It has an interesting plot where the characters from Gravity Falls end up in the Underground world of Undertale. The way the author combines the two universes' elements is really creative.
Another one is 'Unlikely Allies'. It delves deep into how the characters from 'Worm' and 'Gravity Falls' would form alliances. The story is full of action and adventure as they face common threats that are a result of the crossover between the two worlds. It's really exciting to read how the powers and the mysteries of both universes come together.
Character interactions are key. You want to see how the characters from different shows blend together. For example, if it's a crossover with Scooby - Doo, seeing how Shaggy and Dipper would react to the mysteries in Gravity Falls. Also, a good plot that makes sense for both universes. It can't just be a random mash - up.
One popular SCP crossover Gravity Falls fanfic is 'The Anomalous Falls'. It combines the creepy and mysterious elements of SCP with the unique charm of Gravity Falls. Another one could be 'SCP in the Pines' which often has interesting takes on how the SCP entities would interact with the Gravity Falls characters. There are also some lesser - known ones like 'Gravity's Anomalies' that are worth checking out if you're into this crossover genre.
One great place to start looking for Hilda and Gravity Falls crossover fanfiction is Archive of Our Own (AO3). There are many talented writers who combine the two universes in interesting ways. For example, some fanfics might have the characters from Hilda exploring the mysteries of Gravity Falls, or vice versa. The crossovers often play on the similarities between the two shows, like their focus on the supernatural and the adventures of young protagonists.
A great one is 'Naruto in Gravity Falls'. It focuses on Naruto being transported to Gravity Falls. He has to adapt to this new world while still having his ninja skills. His presence in Gravity Falls also starts to affect the balance of the town, and he has to work with the local characters to fix things. The fanfic does a good job of blending the two very different settings.
One popular 'creepypasta crossover gravity falls fanfiction' might be those that combine the strange and mysterious elements of Gravity Falls with the eerie nature of Creepypasta. For example, there could be a story where a Gravity Falls character encounters a well - known Creepypasta entity like Slenderman in the woods of Gravity Falls. The unique settings and characters of Gravity Falls offer a great backdrop for Creepypasta - style horror to unfold.
One idea could be that the ponies from MLP accidentally end up in Gravity Falls. Twilight could be intrigued by the strange anomalies in Gravity Falls and try to study them with Dipper's help. Maybe Pinkie Pie's party - planning skills could be used to liven up Gravity Falls' rather spooky events.
The colorful and magical world of Equestria from MLP could be juxtaposed with the spooky and mysterious Gravity Falls. You could have parts of Gravity Falls, like the Mystery Shack, appear in Equestria. Maybe the ponies think it's a new kind of magical building. Or, have the Gravity Falls forest start to show up in Equestria, with its strange creatures and anomalies.
One possible plot could be that Dipper and Mabel visit Beach City while on a road trip. They meet Steven and the Gems. The Mystery Shack's oddities could interact with Gem magic in strange ways. For example, a Gem artifact might be mistaken for a regular Mystery Shack item and cause chaos when activated.