Stories focused on the family and the friendly relationships of the cast. Plot-focused stories or light day-in-the-life stories. Pretty much anything that isn't focused on romance.
''Enterprise Squared by Bob Regent
Recommended by Judge King
Sypnosis: What if the Enterprise C was unable to return to the past? What does the reality of a war torn Federation really look like?
Synopsis: A leading Starfleet scientist steals classified secrets before apparently dying during an escape attempt; but when he returns five years later, he's meaner and more dangerous than ever, and it falls to his oldest friend to decipher his plan and stop him before it's too late. (Set in the latter TNG era but with a different cast)
Synopsis: In another universe, the Enterprise-C gets destroyed by Klingons before it can enter the rift back into its own time. Picard decides to tell the Temporal Prime Directive to sod off and has the D go back into the past to Set Right What Once Went Wrong. Every decision has consequences, however, and though the war he intended to avert is successfully prevented, it starts to come out that a vast conspiracy was responsible for plunging the galaxy's powers into war, one that will brook no interference.
Synopsis: Shortly after introducing Picard to the Borg, Q has enough of his attitude and decides to test his compassion by sending him to a universe where compassion is in short supply: The Firefly 'Verse.
Synopsis:Serenity's luck never goes well for long, and after that huge piece of luck running into the Enterpise, it comes back to bite him big time. Meanwhile, Picard has to answer for his actions in the 'Verse, and discovers the true meaning of Q's actions.
Sypnosis: A Starfleet Task Force is thrown into the Babylon 5 universe.
Comments: A really good fic that will definitely take several days to read.
YMMV on that one. While the opening chapters are good, and deal with a lot of the problems that Starfleet would encounter as they try to set up a new colony, it eventually settles into Boring Invincible Hero status, bordering on Mary Sue levels of moral superiority over everyone in the Babylon5 universe, which isn't what Babylon 5 is about. Babylon 5 is about ordinary people struggling to survive in a world fantastic and amazing. Will they have flaws? Yes, but that makes them interesting. The Federation has virtually no flaws, and it gets really, really tiring to read page after page of how awesome everything in the Federation is compared to anything in the B5 universe.
I second the recommendation. The Federation does come up as superior, but they are pretty much at the level of First Ones in the B5 universe. The difference is that they try to respect the rights and sovereignty of the less-advanced races. Some of the Federation characters even see their inability to stay isolated and neutral as a failure on their part. So, yeah, YMMV.
Synopsis: A crossover with Portal 2 where the Enterprise encounters a strange orb-like artifact from 21st century Earth.
Comments: Five chapters, each corresponding to the segments as if broken by commercial breaks. Each character is presented and acts as if this were an actual episode of the show. If Portal 2 existed back in the day, and Valve Software felt up to it, this actually COULD have been an episode.
Synopsis: In which Tasha never had the bridge dropped on her, and her relationship with Data throughout the series. "Fate conspired differently. Death passed Tasha by. Given the time to evolve, a relationship she'd dismissed as a one night stand became the most complicated love affair she'd know. Series of stories spanning the show & movies." Now with a TvTropes page!
Comments: Complete with 61 chapters and will be followed up with a sequel, it's an addictive fic, with a great deal of character study, and touching in how vulnerable Data and Yar interact but never OOC. One moment fluffy bordering on crack, the next, heart breakingly tragic. I cannot recommend this enough. Also has a sequel.
YMMV on this. I personally can't second the rec, and feel this reviewer put it best:
"[T]his story seems to mistake nastiness for sexual tension. Tasha is a selfish, petty, spiteful, caustic harpy who makes absolutely everything about her and eternally plays the victim. [...] Data you have as a true automaton (but only when it comes to romance) in a way that - even if I bought that he has no emotions and nothing like emotions - doesn't fit at all with his canon character. [...] These people are awful, this isn't romantic."