i mean the entire fonts, not just headings.
i only know a few: obsidianotion, WY console, spectrum, discordian, and notation 2. what other themes have custom fonts? i didn’t try all of the 267 available themes and don’t want to, honestly, LOL.
I’m sure there are a lot of them. What are you looking for?
Annuppuccin is another theme to try.
i have anuppuccin, it does have custom font, but that only shows in editing mode.
mostly i look for ones that either have changeable custom font (so i can change it to anything), or ones that have a simple elegant sans-serif font like in discord or notion.
ah, yeah, comfort has a custom font too and i quite like that.
You can try Dune, if you want custom fonts, custom initials, etc. 
You can set custom font for interface, text and monospace in core Obsidian (Settings > Appearance > Font). Beyond that, themes that make use of Style Settings plugin will often include the option to set custom ones for each heading, perhaps more, I only ever used Minimal theme.