If they are built-in widgets, it could be that you've unintentionally disabled the correct font. Open Font Book, and make sure that nothing is disabled. Also, check Kurt Lang's
list of required fonts to make sure they're all present and correct.
I too am experiencing this ugly and hard to read font
Checked the system fonts, tossed the dashboard plist
rebooted with sytem disk and repaired volume.
Any other ideas
The problem you are seeing is due to a conflict with the "Helvetica Neue" font. Sometimes a different copy of this font will be installed in your ~/Library/Fonts by a third-party application. If this is the case, remove that copy (either manually or via Font Book) and restart.