Top Ten Tuesday is a weekly meme created at The Broke and the Bookish.
The Obvious Choices: Hermione Granger, Katniss Everdeen, Daenerys Targaryen
To nail this one, you'd either have to use one of Emma-as-Hermione's iconic outfits (for example, the pink jacket and jeans look from Prisoner of Azkaban or her pink Yule Ball dress from Goblet of Fire) or, unlike the movies, stick to the Hogwarts robes (the movie version of which is pictured on the left).
Hermione's frickin' awesome, so this is a great option just for that reason, though of course it's going to be a well-used one for at least a few more years to come. If you happen to have some friends willing to dress up as Harry and Ron (and/or Luna, Ginny, Neville, etcetera), this could be part of a totally awesome group costume.
There are a few options here. There's Katniss's Catching Fire "wedding" dress, its transformed black, winged version, either of her Games uniforms, and her District 13 uniform. Some of the coolest ideas are out of the realm of possibility for most people, such as actually making the "wedding" dress transform, but anything that could evoke "Girl on Fire" imagery would be pretty awesome.
In any case, Daenerys is a fallen princess seeking to reclaim her homeland, which is awesome, and she's got dragons, which is also awesome. And if you show up to a party with a Jon Snow, you'll be the shit (though don't be surprised to see other Danys and Jons there), and if you show up with a Jon and a Tyrion, you officially win Halloween. (You lose points if your Tyrion is not, in fact, played by someone with dwarfism.)
The Gothic Choices: Bellatrix Lestrange and Violet Baudelaire
If you want to dress up as someone generally gothic and don't mind being a villain, Bellatrix is a great way to go. Especially if you've already got the curly dark hair that Bonham Carter rocks in the role!
As for the costume itself, you could base it on one of Browning's film outfits or opt for something more in line with Brett Helquist's illustrations.
The Badass Choices: Alanna of Trebond and Mew Zakuro
That's more work than I'm willing to do, honestly, but I'd love to see someone really go for this! Alanna is freakin' awesome.
This one really would work best if you're Japanese, obviously--which I'm not--but a purple wig, a replica Mew Zakuro uniform, and costume wolf features will get the point across no matter what race you happen to be. And she's got a pretty awesome weapon that's used as a whip, so there's that.
The Childhood Nostalgia Choices: Mrs. Jeepers and Ruth Rose Hathaway
While Mrs. Jeepers may or may not be a vampire, she definitely does wear polka dots, and her other most distinctive features are her green brooch and thick Romanian accent. This is a costume I have never heard anyone even consider using before, nor one that I've ever thought of until today, but I would love to see someone do it!
If you've got curly and/or poofy red hair, Mrs. Jeepers is a great choice (on that note, so is Mrs. Frizzle!)--though don't be surprised if you find yourself having to explain who you're supposed to be! If I ever find a good wig or muster up the courage to go red and curly, I'd totally give a Halloween as Mrs. Jeepers a shot!
I'd love to do this one year.
The Classic Choice: Nancy Drew
Bonita Granville in the 30s and ending (so far!) with Emma Roberts in 2007.
If I were doing this costume, I'd definitely go with a 50s aesthetic, though that's certainly not a requirement. Her blonde hair, though, is definitely a requirement. (And I will resoundingly ignore any assertions that Nancy is "titian-haired". Get your retcons out of here!).