From a World More Full of Weeping by Azar
Doctor Who/Narnia | Tenth Doctor/Post-Books | Short story, complete

Susan Pevensie meets the Doctor.

Crossed Wires by Palgrave
Buffy / Doctor Who | Third Doctor | Short story, complete

In which Buffy jumps to conclusions, but really, it's the Doctor's own fault for wandering Sunnydale dressed like that.

Preludes by seren_ccd
Doctor Who/Sherlock | Pre-series for both shows | Short story, complete

In which Amy Pond and DI Lestrade meet while sneaking cigarettes at a party.

Light Years by idontlikegravy
Doctor Who/Red Dwarf | Tenth Doctor era/Red Dwarf V | Short story, complete

The last Time Lord meets the last human.

The Whitney Street Mystery by Teyla
Doctor Who/House | Tenth Doctor | Novelette, complete

House and Wilson investigate the case of a patient who appears to have two hearts and no lungs.

This is How the Universe Ends by perryvic and shewhoguards
Discworld/Torchwood | Short story, complete

Death, Jack Harkness, and the end of the universe.

A Jaffa, an archaelogist, and two Air Force officers walk into a library by aces
Doctor Who/Stargate SG-1 | SG-1 Season 2 | Short story, complete

The Eleventh Doctor encounters SG-1 in a library.

The Man With No Name by Frostfyre
Doctor Who/Firefly | Post-Serenity | Novel, complete

The Doctor discovers what happened to Earth's Lost Colonists, and the Firefly crew discover a conspiracy.

Five Times the Doctor Got in the Way of Captain Janeway by vvj5
Doctor Who/Star Trek Voyager | Short story, complete

Five times the Doctor got in the way of Captain Janeway, and one time they got along just fine.

What Ho, You Dalek Chaps! by JJPOR
Doctor Who/Jeeves and Wooster | Short story, complete

In which Bertie Wooster deals with some Daleks.