I was trying a few "best to use" fonts:
I will probably switch to Roboto since seems like it be a better one to use, preferred
Also a favorite to me looks like to be Noto Sans 
(aparently developed by google)
Beware of the google fonts ...... for some there's a data collection price. 
I don't really like Roboto. Too "standard" when Elive is trying to be different imo.
I like "Cabin".
"Comic Neue" also might be a good option you want a casual style. It's Comic Sans but actually good. http://comicneue.com/
i just readed in some UX articles that "comic" sans should be never, never, ever, used, in any website, because the pshychological emotion is totally "kiddie" and not serious when a website tries to be
personality is good, but is a dangerous thing (you can filter with that people to not-like a specific preference), by other side elive is pretty customizable (is different but not forced to a specific style), note that this will be not the case of the EliveRetro release (this one WILL have a very specific personality, and thus a very specific and personal font can be a good idea)
standard is not really a problem, the biggest problem (or importance, more exactly) is to have a font to have a good readability, conform for the eyes, not looking strange on the -all- different website contents, make a good feeling, etc...
in summary: if a font with "personality" is picked, needs to be made with very caution, by other side a standard should be the preference but the best looking/feeling one needs to be selected
Cabin doesn't looks bad and seems like to be not "too much personal", has good readability and in a first view doesn't looks like to lose seriousness, will try it a bit more
I agee, it's paramount to have a clean and easily readable font.
I even think we shouldn't want to try exotic fonts (by default) on Retro either, unless we want to keep the high-school kiddo tag.
For websites, I think open sans is good (maybe leave well enough alone?) albeit I agree cabin and noto sans look good too.
