Okay, I am trying not to go overboard here, but I apologize in advance if that doesn't happen. This is also unfortunately heavily weighted toward Gabe/William, because they are my OTP so that's a lot of what I have saved.

Party Games and Goodtime Guys, by jocondite - William/Gabe. If you only read one fic, this should be the one. It is perfection and joy in fic form.

The Notorious Sorcerer's Penultimate Work, by cupiscent - William/Gabe. This is also perfection in fic form, but it was written for me by another lover of fantasy, so if magic doesn't do it for you, this may not be the AU for you. If it does, though, you are in for a hell of a treat.

Always Looking Up, by inlovewithnight - William/various. This is another AU and it tackles some less-than-easy issues, but oh, it is such a beautiful story. It's a great look at William as a character, as well.

Tired Boys and Wired Eyes, by foreverdirt - William/Travis. I have read this story so many times I know parts of it by heart, and I still quote it sometimes to myself at random moments. It's tour-fic, which in bandom is a pretty solid way to my heart.

untitled, by joyfulseeker - William/Jon. This is incredibly short, just a tiny ficlet, but it is so pitch-perfect that I still rank it among one of my favourites in bandom.

I Show Not Your Face, by formerlydf - William/Jon. Harry Potter crossover! This is the fastest way into anyone's heart, right? This story is creative and fantastical and utterly brilliant, and has characters I fell instantly in love with.

skeptics and true believers, by iphignia939 - William/Patrick. This is another of those stories that I have read over and over again. In case you aren't aware, William and Patrick grew up playing in each other's baby bands. Pete and William met at a show where both Patrick and William were playing (acoustic solo guitar, I believe). This is one of very few stories to explore that time, about being young and full of dreams and songs.

Ships That Crash In the Night, by iridescentglow - William/Gabe. Another tour fic, this one going all around the world and back home again.

And if you get through all of those that interest you and want more, my recs are here. :-)