Primeval

Jess/Becker and Abby/Connor when I can find the good stuff. Some gen around the edges.

Alyse @ AO3
One of my favorite Abby/Connor writers.

Prelude in C Minor
Connor finally has the post-series 3 breakdown he so richly deserves, and Abby copes via a road trip to nowhere. Excellent depiction of Connor and Abby dealing with the fallout of everything they've survived -- and the loss of everyone who didn't. Abby/Connor.
Check. Mate.
Abby. Connor. Strip chess. It's much sweeter (and hotter) than you'd think. NC17

Clearing the Decks by Lil Shepard
Tying up the loose ends before the last scene of Season 2 -- and from Lester's POV, no less. I keep forgetting parts of it aren't actually canon.

Just Pretend by RubyCaspar
"I'm aware that this sounds like the beginning of a really bad romantic comedy, but my sister's getting married next weekend and I was wondering if you would go with me to the wedding and pretend to be my girlfriend?" Total romcom, but also quite hilarious and very sweet Becker/Jess. Also try her Into the Woods for somethig a tad plottier (but not much).

Logical by piaffe417
"Scientifically speaking, you shouldn't miss someone who wasn't there in the first place." Nick/Claudia.

Resolution by fringedweller
Becker/Jess course-of-the-series fic, and how fun it is.

Tilted by alyse
"There are only three of them now, although some days it feels like two and one. Her and Connor, and then Cutter, lost out there on his own." Lovely Abby POV in the aftermath of series 2.