Description of problem:
On Fedora 21 (tested with Live Xfce), some fonts look fuzzy. Font types that are affected seems to be Helvetica and Times. I am not sure about which fonts act as 'replacement' for those.
I have attached a screenshot to show how it looks like.
Created attachment 932691 [details]
Font Rendering in Fedora 21 (with Midori used as an example application)
How about on f20 BTW?
Looks better now.