Adrian Tullberg @ Fanfiction.Net
I had to be browbeaten into reading An Unusual Mission, even bribed with choice examples of hysterical dialogue. I didn't watch or read Justice League, my ideas of Wonder Woman still mostly revolved around Lynda Carter, and Batman needs therapy in the worst way. So why would I want to read a story about Bruce and Diana on a date at a charity do? Why would I laugh myself silly doing so? Why would I chortle in glee upon discovering that Adrian continued the one-shot, and fall desperately in love with the 'ship? Well... because it's good!!!! I assume the rest of it (largely comic or cartoon fic) is equally good.
David Hines @ Fanfiction.net
David just kills me -- he can write romance, humor and angst, all of which will bring you to your knees. In Escape Artistry, he grabs a bit of old Wonder Woman continuity -- that she loses her powers when bound by a man -- and uses it to set up a great story, as Batman sets out to teach her how to overcome that weakness. Yes, bondage is involved, yes, the UST runs high. But so does the humor, the solid fight scenes, and the genuinely dead-on characterization, right through to the ending. Measured Out in Coffee Spoons is compelling and heartbreaking, simply written but with exquisite pain running through every word. An Arkham patient has finally found a cure -- now he has to live with it. Or not. I cannot express the excellence of David's writing; check out everything he's ever produced.
Diversions and Digressions
In The Secret Thoughts of a Man, Green Lantern takes advantage of a stake-out to have a talk with Batman, which turns into a short, very well-executed character study of both GL and Bats. One of the better takes on GL I've run into; he's not my favorite, but this made me respect and almost like him. Mara Greengrass also gets into Bats' head very well -- not the easiest of jobs. There's also To Conquer Fear: Gil Grissom and Batman (Forensics Geeks R Us) defending Las Vegas from the Scarecrow with the help of, um, everyone. Written largely in email form, and nicely done.
Chapel of Love
Schmoopy, hilarious, often touching stories of a relationship between Wally West and Smallville's Chloe Sullivan, both as adults and as teenagers (in Sanctuary). These series' made me believe so strongly, my personal JLA:Animated canon includes this relationship. I can't find these archives anywhere anymore, so links are to the Wayback Machine; it's worth it.
Flash by Northwest by MerlinMissy and Dotfic
The Big Seven are mind-napped into a pulp detective novel; their only chance at escape is solving Vixen's murder before they all wind up dead. A great integration of the League (and their Issues) with the conventions of the 40s detective story; Bruce and Wally are especially awesome.
Haunted by Ugly_Girl
Wonder Woman discovers her teammate Batman has been cursed. Breaking it will be the death of her, but she's got help from an unexpected source....
Heart, Humble by brown_betty
I don't read DC comics; all I get from Batman canon are the comments and the fic others write. (Those comments are one of the reasons I don't read DC!). Despite that, I loved this story to death -- Tim Drake through his father's eyes, post discovery of Robin's secret identity. Jack's character was evidently massacred in the comics -- brown_betty's version is not Mr. Perfect, but is human, and loves his son. If you know the Bat-verse at all, this one is worth your time.
In Darkest Light by Meljean Brook
The problems of Bruce and Diana's relationship -- from saving the dimensions from the Joker to dealing with a completely unexpected attraction to each other -- are handled with no punches pulled. A satisfying, adult romance.
Someone Like You by Reichenbach
The Birds of Prey pilot presented a few annoying questions -- mostly, how Bruce never knew he had a daughter when he and Selena were living in New Gotham the whole time. This offers a plausible answer.
The Stolen Child by Merlin Missy
A painful, probable tale of three traumatized orphans, and their search for where and when they belong. The Batclan is beautifully and painfully portrayed, and both Green Lantern and Shayera are nicely drawn.
Batman Begins universe
The Longer You Stay by emiv
"Bruce Wayne was never meant to be part of Selina's clean slate. Then again, neither were a circus boy, a street rat or a rich kid. For a girl who didn't like strings, Selina found herself getting attached." Or, nothing can stop the BatFamily from forming. Very solid Selena POV; my heart melted at several points. KikiRec
Passing the Baton by quiet__tiger
Excellent post-Rises Blake, settling into his new role. Bonus!Lucius.
Q&A by Medie
Vicky Vale doesn't believe Bruce burned down Wayne Manor. Actually, there's a lot Vicki doesn't believe.... Really nice -- someone with a brain picking apart the holes in Batman's cover.