Sorry for the accidental double-rec: here, have this one instead!
Story:
Boys (or, Down With The Patriarchy!)Author: uktechgirl
Rating: All Ages
Author's summary: Doctor Who/Angel crossover. Shortly after taking up residence at Wolfram and Hart, Angel’s office plays host to a certain blue box.
Characters/Pairings: Ace/Fred, Seventh Doctor, various Angel characters
Warnings: none
Word Count: ~3,400 words
Recced because: This is an absolutely brilliant story. The crossover really and truly works (and I'm not generally a fan of Angel, so it had to work extra hard for me), bringing in Ace, who has something of a Slayer about her, and intertwining Fred and Ace's storylines, as well as the mythologies of both shows, all without trying too hard and forcing things that don't fit. All of the voices, from both teams, are dead-on perfect (Angel at the beginning is particularly hilarious), and the style is intriguing and manages to be appropriately serious while also having a light touch. And Ace and Fred make a fabulous team, with the relationship aspect played softly, hinting at something between the two women that could be amazing.