The Ubuntu folks seem to change around their default font settings every release. Whatever that’s fine. But it is worth nothing that the default “subpixel” setting in the gnome appearance dialog now means “subpixel + slight hinting” whereas previously it meant “subpixel + full hinting”
Since 8.04, though, they’ve committed a crime, IMHO. There’s some new fontconfig magic which automatically aliases “Times” to the “Nimbus Roman” family (or Liberation, if you have it installed), both which render like crap. Those fonts used to resolve to the DejaVu family, which while look different from Times and Helvetica and the like for which they serve as substitutes, still render acceptably under the “subpixel + full hinting” mode.
As far as I’m concerned, there are only five fonts that render well on Linux under this mode. Dejavu Sans, Serif, and Mono, and Droid Sans and Mono. Any settings that cause any fonts other than these to get picked should be avoided.
Thankfully, on 8.10, it’s pretty easy to restore the old behavior. Go into your /etc/fonts/conf.d directory and delete 30-metric-aliases.conf and 30-urw-aliases.conf.
You can verify the settings are now correct by typing fc-match "Times" in a terminal, and making sure “DejaVu Serif” is returned.
Speaking of which, I thought Liberation fonts were supposed to look good under Linux. Why do they still look like crap?