I think possibly the most famous are the scrolls discovered in Herculaneum.

Herculaneum was destroyed in the same eruption as Pompeii, but unlike Pompeii, was completely destroyed by pyroclastic flow, the exceptionally high temperature of which carbonised certain objects, preserving them, objects like bed frames, and, notably, what appears to be an entire library of scrolls.

The scrolls were discovered in 1752, and over the subsequent years around 1800 or so scrolls or fragments were discovered. There have been various attempts to open the scrolls, with some very limited success because carbonisation has made the scrolls exceptionally fragile. Some attempts destroyed the scrolls, or destroyed the writing visible in the scrolls, and these attempts have meant the around 400 or so scrolls have been waiting for a long time for technology to catch up.

There have been some developments using CT scans (someone more techy than me might be able to explain more accurately what I mean) which looks at the difference of lead in the ink compared to the parchment and virtually unrolls the scrolls, but the tightness to which the scrolls have been wound (or perhaps shrunk in the pyroclastic flow) makes this an exceptionally difficult thing to achieve.

What has been discovered includes works by Chrysippus, whose work was thought entirely lost, and works by Epicurus, and most recently works by Seneca the Elder have been identified. It’s pretty much anyone’s guess as to what other works might be found. Given what has been identified, I wouldn’t expect there to suddenly be a major collection of the works of Sappho (having said that some fragments of Sappho did emerge recently by separating out Ancient Egyptian cartonage ie papier-mâché). EDIT: My bad Sappho is obviously Greek, not Latin like you asked. Don’t expects new work by Augustus or Cicero, you get the picture.

Tantalisingly, the villa where the scrolls were found has only partially been excavated, and most of the works discovered were mostly in Greek although some are in Latin. There has been a lot of speculation that a further Latin library is still waiting to be discovered. Given the Italian government’s reticence to allow more excavation at Herculaneum, we may not know for a lot longer.

Otherwise, there are still around half a million fragments of ancient papyrus manuscripts to be pieced together and translated from the ancient rubbish dump of Oxyrhynchus, though these very much are fragments and so it’s very unlikely there would be a discovery of a complete or even half of a text. Fragments by known Greek writers have been discovered, but there’s also fragments of correspondence and administrative documents and so on. While mostly in Greek, it’s conceivable that there could be Latin fragments somewhere in what was recovered.

I’m also aware that the majority of the Bloomberg tablets, discovered in London quite recently, have yet to be analysed and the scratch marks left on backing wood on what were wax covered tablets analysed. These are unlikely to uncover any major works by known writers, but they are showing some interesting correspondence and administrative documents of Roman Britain.

There’s also almost definitely a number of later Latin writers, even some pretty famous Christian writers considered maybe too unimportant or too niche by some, who have been transcribed and maybe published sometime in last 150 to 600 years in Latin but which have not been translated yet.

There could be still more texts out there, archaeologists just never know when some papyrus or palimpsest is going to emerge from a private collection, and there are still some discoveries coming out of Egypt and there are still discoveries of correspondence coming from Hadrian’s Wall in the United Kingdom.