The M/M Rares fest is still taking sign ups until 8PM PDT on Friday, May 23rd. (That's west coast USA time.)
comm on Dreamwidth comm on AO3 FAQ all the available pairs A number of DCU rare pairs were nominated for the exchange.
DC Animated Universe
Barry Allen/Hal Jordan (DCAU)
Justice League & Justice League Unlimited (Cartoons)
Clark Kent/Bruce Wayne (JL & JLU)
John Stewart/Wally West
Kon-El/Clark Kent
Kon-El/Lex Luthor
Justice League of America (Comics)
Barry Allen/Hal Jordan
John Stewart/Wally West (Comics)
Kon-El/Clark Kent
Young Justice
Barry Allen/Wally West
Dick Grayson/Bruce Wayne (Young Justice)
John Stewart/Wally West (Young Justice)
Kon-El/Clark Kent
Kon-El/Lex Luthor
The Sandman (Comics)
Cluracan/Loki
Dream of the Endless/Pharamond | Mr Farell
Hob Gadling/Bhartari Raja
Lucien/Bhartari Raja
Arrow (TV 2012)
John Diggle/Slade Wilson
John Diggle/Oliver Queen
Oliver Queen/Slade Wilson
Roy Harper/Oliver Queen
Tommy Merlyn/Oliver Queen
Crossover pairs (listed in the "No Media" section of the sign up)
Billy Kaplan (Young Avengers)/Klarion (Young Justice)
John Stewart (Justice League Cartoon)/Wally West (Young Justice Cartoon)
Kaldur'ahm (Young Justice (Cartoon))/Richie Foley (Static Shock)
Klarion (Young Justice)/Loki (Agent of Asgard)
Teddy Altman (Young Avengers)/Kon-El (Young Justice)
Tommy Shepherd (Young Avengers)/Wally West (Young Justice)
Tom Riddle (Harry Potter)/Cluracan (Sandman)
To play you need to submit 4-6 requests and 4-10 offers. Each request must be for a unique fandom (there are a bunch of DC fandoms included) and may include up to 10 pairings. Each offer must be for a unique fandom and can include up to 20 pairings. For offers, you may also check 'Any' if you're willing and able to create for any pairing listed under the fandom heading.