http://www.portkey.org/
An archive that hosts fanfiction and artwork for the ships of Harry/Hermione, Lily/James, Draco/Ginny and Ron/Luna.

http://dark-methods.net/er/
A Draco and Luna fanfiction archive and community

http://ashwinder.sycophanthex.com/
An archive for Hermione Granger and Severus Snape fanfiction.

http://www.thehexfiles.net/
A Draco and Harry slash archive.

http://www.siye.co.uk/siye/
A large fanfiction archive revolving around Harry and Ginny

http://www.dracoandginny.com/
A large fanfiction arhcive for fics revolving around Draco and Ginny

http://www.nevilleandluna.com/fanfiction/
A Neville and Luna fanfiction archive and community

http://www.fire-vs-ice.net/
Mega Ron/Draco Slash Archive. Fanart as well as many gorgeous stories containing the two honeys.

http://hc.potteritus.net/fanfiction
A slash fanfiction archive dedicated to our favorite tragic One True Pairing, Harry Potter and Cedric Diggory.