For me, Trebuchet goes straight to my brain. There are plenty of fonts that look nicer to me, but that's the one that I settled on after trying out dozens. I read it faster, I don't lose my place, it works equally well for me at several font sizes and on both traditional ebook readers and tablet screens.

nztt.

Made it myself.

Works for my dyslexia, and efficient for vertical space.

It divides opinion, some very enthusiastic, some hate it.

http://vollkorn-typeface.com/ And I’m surprised that no one mentioned it yet

Faustina, it's the FOSS alternative to the Kindle's default font.

OpenDyslexic. I used to hate reading. Read one and a half books this year. Also 3 novella's. For fun! I never read for fun. Usually just programming books to get my feet wet before jumping into documentation. Never an entire book cover to cover unless Im obsessed enough.

I was sceptical but it really does help.

Times New Roman

/not allowed to say anything else or my boat will be sunk.

Atkinson Hyperlegible Next from the Braille Institute

Usually whatever the default serif typeface is. What I care more about is flush left (“ragged right”) alignment, ideally with automatic hyphenation. I find justified alignment very distracting.

Problems with justification » Typographic anomalies

Lexend Deca from https://www.lexend.com/ because it's the only font I could find which was studied during it's creation for being more readable for many people.

Noto Serif

you can change fonts on ebooks?

Gentium Book, Alegreya, or Labrada. Humanist serif fonts for reading Fantasy and SciFi. Absolutely love them, can't recommend these enough.

comics sans

Shantell Sans

Roboto, Droid, Dejavu, Liberation. Only Sans Serif.

Antykwa Torunski.

Since the first time of seeing it on a Mac (Plus, probably), I've been in love with Palatino. It just seems to flow so nicely, and the italic is gorgeous.

I missed it for many years until I found TeX Gyre Pagella.

Literata and Bitter Pro are the ones I switch between on my kobo.

Libertinus Serif is my current favorite. I generally like most garamond-likes for most books, but will dabble in a sans if the book is suitably scifi. Older favorites of mine are Adobe Caslon Pro and Adobe Devanagari. Baumschrift is a fantastic clean sans font but honestly it shines best on larger sizes for headers rather than prose. If we are doing monospace I love IBM Plex Mono in the light variety.

Any serif font is fine by me. I've been going with whatever Zathura's default epub font is.

During last year, I have been using Liberation Serif on my Kobo Clara Reader.

Copperplate Gothic.

Just kidding, I don't have one but would love some suggestions.

Georgia

Baskerville, or Jokerman if I fancy an aneurism.

Currently using Noto Sans in koreader

I just tried a few fonts on my old Kobo, as I've done a few times here and there, and I always end up back with a serif font. I'm not sure why, but I have suspicion that reading paperbacks and newspapers before ereaders existed has trained me to read faster with serif fonts.

i experimented with a test that boldened only the first half of the word or something similar, years ago. i'm dying to find something that an read ebooks like this, i can read twice as fast with it.

Vollkorn. The best I could find.

Yes.

TL;DR: I don't actually know, that's how much I care.

Comic sans.

Just kidding. I use the dyslexia font. It does what it says on the tin.

I prefer a helv variant usually, but now that it's under fire I'm trying out colibri.

The specific font isn't as important for me. Mostly I'll use whatever sans serif option is available in the reader, since I generally despise serifs. Very occasionally I'll go for a serif font on a fantasy book for "atmosphere", though.

Inter.