Good places to check are the old Yuletide archive (http://yuletidetreasure.org/archive/fandom_odyssey_5.html) and Loony Archivist (http://www.loony-archivist.com/o5/fanfic.htm). There are some on the ff.net and WWOMB as well if you're prepared to dig!
December 23rd, 2002 (http://taraljc.livejournal.com/592974.html) by taraljc. Set after "Follow the Leader." Both times December 23rd, 2002 had rolled around for Neil Taggart, it had rained like a sonofabitch. (R rated). This fic has Neil directly comparing the repeat of one day with it's predecessor. Neither are overwhelmingly brilliant. It's full of angst and really sums up beautifully Neil's feelings on the way his life is turning out (again).
Scientific Method (http://www.loony-archivist.com/o5/fiction/scientific.htm) by Tiriel Set after "Half-Life". Neil has a lot on his mind. (Kurt/Neil. R rated.)
The Random Frantic Action that We Take (http://archiveofourown.org/works/32829?view_adult=true) by shift "I wish you could remind me of who I was / because every day I'm a little further off." (Kurt/Neil, Angela/Kurt. NC-17 rated). This was my gifted fic from Yuletide 2009 and I am convinced it is the best fic in the fandom. Set after the series finale (with spoilers), and set from Neil's POV you have him trying to seek comfort in Kurt but being screwed over and his attempts to deal with being in a seventeen year old's body again.
Living in Yesterday (http://www.loony-archivist.com/o5/fiction/yesterday.htm) by Kira Kurt reflects on the mission's success so far and what sacrifices might have to be made in the future. (Kurt/Neil. NC-17 rated). I'm not normally a big fan of first person fic, but this one really does work. Again it's heavy and angsty but I do still love it. :) Set after the end of the series and his scientifically-minded way Kurt watches everyone else and analyses the situation.
This is me Breathing (http://yuletidetreasure.org/archive/16/thisis.html) by estrella Angela had been missing for over three years when she walked into the diner one late September afternoon. (Angela/Kurt. R rated). There's a lot of Kurt in these fics - he seems to feature heavily in the very small fandom. But he's also fun to explore. Set after the end of the series (spoilers), Angela has been missing and returns. Kurt is delighted to have her back but is everything as it seems?
Fated (http://www.loony-archivist.com/o5/fiction/fated.htm) by Konstantine. In the end they don't win. (Kurt/Sarah. R rated). One thing about a smaller fandom is you'll try pairings that you won't normally. This isn't one I would have ever considered in a bigger fandom but it really works! Kurt and Sarah turn to each other because there's no-one else around that understands what they're going through.
Formica Bubble (http://www.loony-archivist.com/o5/fiction/formica.htm) by Suz The day the world ended. Only not. (R rated). Set after the series (and has spoilers for the whole of it) but this is Kurt and Chuck in the diner on the day the world was supposed to explode. A very melancholy tone and gives a satisfying conclusion to where each of the characters may have ended up.
The last one you will love if you like Kurt. Let me give you an extract to tempt you.
The day the world ended, Kurt had paté on toast for breakfast.
Not just any paté, of course. It was the rarest, most expensive paté he could find within a twelve-block area of his apartment. It didn't matter if it was an orgasmic experience against his tongue, or made his taste buds want to commit harakiri—the fact was that he was still Kurt Mendel, and there were certain expectations that came with that.
Also, not as a rec but I've got an Odyssey 5 bigbang story at kipperific. If you like apocafic. Which since you liked the show... :)
Re: I'm aware that there's no way this doesn't look stalkery...since you don't know me but -
December 23rd, 2002 (http://taraljc.livejournal.com/592974.html) by
Set after "Follow the Leader." Both times December 23rd, 2002 had rolled around for Neil Taggart, it had rained like a sonofabitch. (R rated).
This fic has Neil directly comparing the repeat of one day with it's predecessor. Neither are overwhelmingly brilliant. It's full of angst and really sums up beautifully Neil's feelings on the way his life is turning out (again).
Scientific Method (http://www.loony-archivist.com/o5/fiction/scientific.htm) by Tiriel
Set after "Half-Life". Neil has a lot on his mind. (Kurt/Neil. R rated.)
The Random Frantic Action that We Take (http://archiveofourown.org/works/32829?view_adult=true) by shift
"I wish you could remind me of who I was / because every day I'm a little further off." (Kurt/Neil, Angela/Kurt. NC-17 rated).
This was my gifted fic from Yuletide 2009 and I am convinced it is the best fic in the fandom. Set after the series finale (with spoilers), and set from Neil's POV you have him trying to seek comfort in Kurt but being screwed over and his attempts to deal with being in a seventeen year old's body again.
Living in Yesterday (http://www.loony-archivist.com/o5/fiction/yesterday.htm) by Kira
Kurt reflects on the mission's success so far and what sacrifices might have to be made in the future. (Kurt/Neil. NC-17 rated).
I'm not normally a big fan of first person fic, but this one really does work. Again it's heavy and angsty but I do still love it. :) Set after the end of the series and his scientifically-minded way Kurt watches everyone else and analyses the situation.
This is me Breathing (http://yuletidetreasure.org/archive/16/thisis.html) by estrella
Angela had been missing for over three years when she walked into the diner one late September afternoon. (Angela/Kurt. R rated).
There's a lot of Kurt in these fics - he seems to feature heavily in the very small fandom. But he's also fun to explore. Set after the end of the series (spoilers), Angela has been missing and returns. Kurt is delighted to have her back but is everything as it seems?
Fated (http://www.loony-archivist.com/o5/fiction/fated.htm) by Konstantine.
In the end they don't win. (Kurt/Sarah. R rated).
One thing about a smaller fandom is you'll try pairings that you won't normally. This isn't one I would have ever considered in a bigger fandom but it really works! Kurt and Sarah turn to each other because there's no-one else around that understands what they're going through.
Formica Bubble (http://www.loony-archivist.com/o5/fiction/formica.htm) by Suz
The day the world ended. Only not. (R rated).
Set after the series (and has spoilers for the whole of it) but this is Kurt and Chuck in the diner on the day the world was supposed to explode. A very melancholy tone and gives a satisfying conclusion to where each of the characters may have ended up.
The last one you will love if you like Kurt. Let me give you an extract to tempt you.
The day the world ended, Kurt had paté on toast for breakfast.
Not just any paté, of course. It was the rarest, most expensive paté he could find within a twelve-block area of his apartment. It didn't matter if it was an orgasmic experience against his tongue, or made his taste buds want to commit harakiri—the fact was that he was still Kurt Mendel, and there were certain expectations that came with that.
Also, not as a rec but I've got an Odyssey 5 bigbang story at