Historical Gaps, by The Cyan Recluse
Zero-ish spoiler summary: Equestrian history is full of forgotten civilizations, relics, and stories. Daring Do has learned many of them... but she's careful not to let too much truth into her stories. Some truths are better off lost.
A few thoughts: For all that this is, at its heart, a pretty typical take on soft Tyrantlestia ("soft Tyrantlestia" meaning that she's working for the greater good and regrets the measures she's taken), it does a nice job of not getting too dark for its own good. In addition, it uses its shifts from past to present and back to good effect, keeping the pace up through constant switches. It never quite reconciles "genocide-inflicter" with "Celestia," though--one's ability to accept that premise is likely to guide how much one can enjoy this story. It also has a fair number of editing errors (mostly missing commas and spellcheck errors); not enough to impede comprehension at any point, but a sufficient number to be a distraction.
Recommendation: If you enjoy tales about a more vicious past, and aren't put off by slightly shaky writing, give this a look. It's probably not a good fit for anyone who can't see Celestia committing mass-murder in the distant past, though--or at least, who can't provide their own explanation for how she's changed between then and the show's present-day.
Final Mashtination, by Rinnaul
Zero-ish spoiler summary: Button Mash wakes up one morning to discover that the universe is conspiring to kill him in increasingly unfair ways--every time he restarts
A few thoughts: While I may not be much for video games, I know all about unfair deaths--I've had more than a couple of characters unjustly done in over the course of twenty years of D&D-playing. So some of the ways Mash tries to deal with an unfair DM are entirely relatable to me, which really helped my enjoyment of this fic. Ending framing device notwithstanding, this is basically just variations on the summary's concept, but it's short enough (and has enough variations on that concept) to keep it from getting stale before it concludes.
Recommendation: If you're in the market for something quick and silly that takes death exactly as serious as gamers ever do, this would be an excellent choice. But if you aren't at least a little intrigued by the summary, it's probably not the fic for you--there's not a lot else here.
That Place Beyond the Sea..., by Skyblitz
Zero-ish spoiler summary: Twilight and Celestia go to the shore of the Eternal Sea. All of Twilight's friends have passed on--and unbeknownst to her, she now faces a choice.
A few thoughts: There's some really lovely imagery in this piece, with frankly beautiful descriptions (of location, especially) which are florid but fitting for the tone of the fic. Unfortunately, the rest of the story isn't up to the standards of those descriptions. The plot is one that I've seen in stories many times, the setup is over reliant on stringing the reader along, and far too much of the story involves quoting Enya. Not full block quotes of characters reciting lyrics, thank goodness, but enough lines from the LotR soundtrack to detract from the reading experience.
Recommendation: If you're still relatively fresh to the fandom and haven't burned out on this particular brand of immortality angst, and if you like your prose on the purplish side (but not inappropriately so), this would be a serviceable example of the genre. Otherwise, it's probably not the best fic for you.