Tumblrs, start your engines: the mtvU Fandom Awards are kicking off a competition specifically for you, to determine once and for all which fandom on everyone's favorite microblogging platform is our BFF (that's Best Fandom Forever, of course.)

Starting today, six fabulous fandoms have the opportunity to rise to the top and rule them all, starting on MTV's own tumblr. We've created one unique post for each of the Best Fandom Forever nominees, with voting open through July 23. And because this is Tumblr, you know the drill: whoever has the most notes, wins. Which group of pop culture enthusiasts will emerge victorious as our BFF? Read on for a rundown of the nominees.

"Harry Potter"

Before we go any further, it should be noted that the power of the Harry Potter fandom is such that even now, years after the conclusion of both J.K. Rowling's series and its movie adaptations, Potterheads still managed yesterday to basically

" target=_"blank">break the internet. Best fandom ever? You're damn right it is. This fandom eats Harry Potter. They

" target=_"blank">sleep Harry Potter. They ARE Harry Potter! And when it comes to winning this competition, Harry Potter himself has nothing but confidence in his followers.

"The Lord of the Rings"

One does not simply walk into Mordor, and one does not simply like "The Lord of the Rings." What makes this fandom the best? There's the

" target=_"blank">Gollum paparazzi art, for starters; and of course, the hundreds of fans who are planning their very own elvish weddings. And without this fandom, would we have ever known the glory of the 10 HOUR REMIX of "They're Taking the Hobbits to Isengard"?

"Buffy the Vampire Slayer"

Buffy might be gone from primetime, but thanks to her fandom (and the series' perpetual presence on Netflix instant) she and the rest of her friends from the Hellmouth will never be forgotten. How dedicated are the Buffistas of Tumblr? Let's put it this way: We strongly suspect that they and their enthusiasm are single-handedly responsible for bringing late 1990s fashion back into style. And Buffy is still fully capable of saving the world, thank you very much, just as she's fully capable of staking her competitors into piles of dust.

"Doctor Who"

The Whovian presence on Tumblr is a force to be reckoned with. They can find the perfect "Doctor Who" quote to fit any situation. They can draw a photorealistic picture of Matt Smith wearing a bow tie in less than .03 seconds. They are freakin' covered in Tardis tattoos. Will they destroy their competition in the BFF category? Let's just say that someone whose opinion we greatly respect says there's a durn good chance.

"Sherlock"

If you're not sold on the importance of the Sherlock fandom, you might want to start with the part where Sherlockians everywhere have singlehandedly made a man who looks like an otter into an international sex icon. The BBC's boys from Baker Street have launched thousands of tumblrs devoted to them, with fans sharing everything from art to playlists to crafting projects to knitwear based on the wallpaper from 221B Baker Street. But the best proof of this fandom's superiority? Their passionate shipping of a certain pair is the whole entire reason that this gif even exists.

"Batman"

Is Batman's fandom the best? Well, it's arguably the broadest and most far-reaching; Tumblr is home to myriad fans of every single one of the Caped Crusader's many iterations, from Christian Bale's gravel-voiced vigilante to his comic-book predecessor from the 1950s. And it doesn't end there! There's Batman nail art. There are batcats and batpugs. There are blogs devoted exclusively to Gotham City's femmes fatales. And let's not forget that thousands (if not millions!) of tumblrs have laughed at the Joker's boner, despite explicit instructions to the contrary. Will Batman be our BFF?

Head to MTV.Tumblr.com to vote for your favorite now!