Discovering the existence of this community led me to tag crossovers I have written in my delicious. Among the crossovers between 24 different fandoms (many books, some TV, some comics, and the occasional musical) indexed here, I am particularly fond of the following:
Twice is a coincidence (Leverage/White Collar, Hardison and Clinton Jones do not exactly fight crime, PG-13)
Lay that damned book aside (Good Omens/Promethean Age, Aziraphale has a fling with a different sort of devil, R)
Where winter wolves bark (due South/A Companion to Wolves, an amalgam of Benton Fraser and a world with sapient wolf companions, R)
Sparrowhawk (Supreme Power/DCU, Kyle the angry Batman analogue gets the happiest Robin ever, series G-NC-17)
Five universes the Doctor never visited (DCU, Rosencrantz and Guildenstern are Dead, Vorkosigan, Temeraire, due South, G)
All thee Dysk's a Stage (Discworld/Slings & Arrows, Darren Nichols staging audience participation is deadly, G)
Twice is a coincidence (Leverage/White Collar, Hardison and Clinton Jones do not exactly fight crime, PG-13)
Lay that damned book aside (Good Omens/Promethean Age, Aziraphale has a fling with a different sort of devil, R)
Where winter wolves bark (due South/A Companion to Wolves, an amalgam of Benton Fraser and a world with sapient wolf companions, R)
Sparrowhawk (Supreme Power/DCU, Kyle the angry Batman analogue gets the happiest Robin ever, series G-NC-17)
Five universes the Doctor never visited (DCU, Rosencrantz and Guildenstern are Dead, Vorkosigan, Temeraire, due South, G)
All thee Dysk's a Stage (Discworld/Slings & Arrows, Darren Nichols staging audience participation is deadly, G)