I began making recommendations in April of 1998, and I think I've done pretty well with my picks -- a surprising number of these stories have gone on to win awards from the fans :)
(11/29) Lois & Clark Season 6, by a talented group of authors. When the show went off the air, this group of FOLCs refused to let it die. There were 22 episodes of Season 5, and there are 14 episodes of Season 6. These are written to mimic actual episodes, with villains and A-plots and continuity, oh my! And the season ended with a tremendous bang <g>
(11/24) Jaci Morand would like to recommend Full Circle, by Crystal Wimmer. She describes it as a sweet story that tells about Lois & Clark's son, CJ -- about how he has to deal with his new superpowers, his dad being Superman, and his best friend Kat.
(11/24) Jaci also recommends A Shot in the Dark, by Sheila Harper. This is a story that describes how Lois & Clark deal with a tragedy; the kind of story where you hate the villain and love the commitment that L&C have to each other. The feel-good ending makes you happy that you read it, but sorry that it wasn't longer!
(10/31) Lois and Clark and Silver and Bruce, by Phil Atcliffe. What if Bruce Wayne came to Metropolis, and ran into an old flame? What if Batman and Superman's secret identities weren't all that secret -- at least not from the women they love. This is a less a crossover-superhero fic than a relationship fic and I still maintain that it should have won a Kerth.
(10/31) And for you nfic readers out there (over 18, please), I'm pleased to recommend Sugar and Spice, by DocKlein's LabRat. This is a lovely little story, wherein L&C's relationship abruptly shifts into overdrive, then hits a few speed bumps before evening out again... It starts off with an extended tease, but it does get really good later <g> Since it is adult in nature, I can't link to it directly, but it's available from Anne's Nfic Archive (instructions on how to receive the password can be found on her site). Update: There's now a PG-13 version available! :-)
(10/6) My Adventures with Superman, by Kathryn Ann Kent. When young Katy Kent discovers that her parents are supposed to be friends with Superman, she decides to invite him to dinner ... and not even Lois can easily change her daughter's mind. A very cute & charming tale.
(10/6) May Shaheen would like to recommend That the World May Know by Rachel Smith. The description from the archive says: "Speculation runs wild when Superman is found unconscious and wounded -- and disguised in a business suit -- in an alley behind the Daily Planet." May told me she could really identify with the characters, and the story kept her on the edge of her seat most of the way through.
(9/24) You Made Me Love You / Wheels of Justice / Great Shades of Elvis by Zoomway. This series is a bit unusual in that we not only have a revelation, we have a great aftermath, with the beginnings of a wonderful partnership as L&C work out their new relationship. Great character moments throughout. And if you've ever wondered why Mayson is so widely seen as a xenophobe, absent any evidence on the show, well, these stories are the reason - a great example of fan canon.
(9/24) Wendy Richards would like to recommend The Huntress' Revenge, by Jenni Debbage. She says it's a long story, in which three of Clark's bitterest female enemies (Gretchen Kelly, Diana Stride, and Mindy Church) conspire to expose his secret and rid the world of Superman. The action is handled extremely well, Wendy reports, and the ending features help from an unexpected quarter, arriving just in time. "A wonderful and very well-worked story." Thanks, Wendy, for contributing :-)
(8/27) A World Without Superman Mr. Mxyzptlk comes back, with a little test for Lois -- suppose he sends her back in time to when Clark first arrived at the Planet, only he didn't have powers, and never had. Things will only revert to normal if she can somehow convince him, against all evidence, that he's Superman... (This is a Round Robin fanfic written by multiple authors)
(8/9) Reminiscing, by Leigh Raglan. Written & set near the end of the second season, L&C look back at some pivotal moments in their relationship -- and arrive at a new turning point.
(7/18) Trapped, by Michele Savage. Step into the way-back machine for an early story set in the first season :-) Lois & Clark are visiting a museum together when an earthquake brings it down around their ears. And the debris is unstable enough that Clark can't risk moving it, so he comforts Lois as best he can...
(7/6) In The Beginning by B.B. Medos. This is an alternate look at the pilot; what might have been different if Lois had glimpsed Clark doing something "super" before Superman arrived on the scene... It was nominated for a Kerth Award for Alternate Beginnings.
(6/21) Recognition (Truth) by Carol Malo. Lois and Clark attempt to unravel a forty year old murder mystery in Minnesota while, at the same time, they confront their mutually intensifying feelings for each other. Set in the middle of the second season, it's long, but worthwhile. The sequel is now available, too: Recognition (Justice)
(6/11) Quick Change by Carla Humbert. Subtitled, "or, How to Go From Farmboy to Superhero in One Second or Less." We saw Martha create the Superman costume, and we saw that Clark initially had some trouble changing into it... this little story shows how the spin change might have been perfected. It was nominated for a Kerth in the "Best Comedy" category.
(5/23) Montrose's Toast, by Phil Atcliffe. This is Phil's continuation on a previous fanfic, "Sold! The Metropolis Bachelor Auction Incident" by Erin Dawn McInnis (available on the archive). Lois went to the auction prepared to bid her life's savings to get a date with Superman, but when Mayson began bidding on Clark, Lois just had to outbid her. Now that's she's won the date with Clark, the real fun begins... (this is an alternate universe story, branching off from early second season).
(5/6) Then Came You/Two Become One This is Jeff Brogden's two-part episode for TUFS, a terrific resolution of the Alt-Clark story... Clark wants nothing more than to find "that one great love", his soul mate, Lois Lane. But she hasn't been heard from since she disappeared in the Congo, years ago, and he's strangely drawn to new Planet employee Amanda Hart. Little does he know that Amanda is really Lois Lane, in disguise -- she didn't just disappear, she was set up, and she's determined to find out why and by who. Will Amanda find out the truth in time? Will Clark allow himself to notice "ordinary girl" Amanda when he's starstruck by "superreporter" Lois Lane? (Now also available on the archive)
(4/27) Heartbeat by Jennifer (Jiji) Baker. This is a sweet little WAFFy fic that was somehow overlooked in Kerth nominations. And the most remarkable thing about it is that it was written over 3 years ago, back when FOLCs were hoping desperately for the start of a relationship, and for a revelation. Jiji was wonderfully ahead of her time - enjoy!
General Disclaimer: None of us own copyrights to Superman, Clark, Lois, etc, etc; they belong to DC Comics, Warner Bros, and who knows who else. We're just borrowing them to have fun; we're not making any money at this. And the fanfics recommended here represent my taste alone; there are tons of wonderful stories out there, way more than I will ever have time to list here.