I don't know what you've read and what you haven't, but here are a few lengthy qaf tearjerkers I loved -
Reaper Boy, a Dead Like Me/Queer as Folk crossover by wrenlet. You start here (http://www.livejournal.com/users/nanowrenlet/430.html) and then continue through the journal, clicking on 'next entry' each time you've completed a section as it's laid out chronologically in the lj without chapter/part designations.
If You Needed Me (http://www.toolunaticsnwon.com/html/myrna_s_fiction.html) by Myrna, a series made up of four parts - If You Needed Me, I Would Come To You, I'd Swim The Seas, and For To Ease Your Pain from Ethan, Michael, Brian, and Justin's points of view, respectively.
Thanksgiving (http://yearningvoid.net/stories/qafgrocery/000054.html) by Myrna
Intermission (http://www.morpheusqaf.com/Intermission.html) by Morpheus
Name Your Wish (http://www.geocities.com/qafjv/justvisiting.html) by Just Visiting
Rhi's fics - Omelet and Deeper Than Death found here (http://www.rhiannonhero.net/) on her site
From A Safe Distance (http://www.livejournal.com/tools/memories.bml?user=bigboobedcanuck&keyword=QAF+Fic&filter=all) by bigboobedcanuck - Just scroll down to the links.
The Cause (http://www.livejournal.com/users/juteux/31036.html) by juteux
no subject
Reaper Boy, a Dead Like Me/Queer as Folk crossover by
If You Needed Me (http://www.toolunaticsnwon.com/html/myrna_s_fiction.html) by Myrna, a series made up of four parts - If You Needed Me, I Would Come To You, I'd Swim The Seas, and For To Ease Your Pain from Ethan, Michael, Brian, and Justin's points of view, respectively.
Thanksgiving (http://yearningvoid.net/stories/qafgrocery/000054.html) by Myrna
Intermission (http://www.morpheusqaf.com/Intermission.html) by Morpheus
Name Your Wish (http://www.geocities.com/qafjv/justvisiting.html) by Just Visiting
Rhi's fics - Omelet and Deeper Than Death found here (http://www.rhiannonhero.net/) on her site
From A Safe Distance (http://www.livejournal.com/tools/memories.bml?user=bigboobedcanuck&keyword=QAF+Fic&filter=all) by
The Cause (http://www.livejournal.com/users/juteux/31036.html) by