These are my top Ubuntu bugs. Feel free to confirm any bugs that affects you by clicking on the +affectsmetoo link.

clipboard

The clipboard deletes content in the clipboard when quitting the source program. This means Copy -> Quit -> (Can't Paste). Workaround Available: parcellite

• Copy-Paste doesn't work if the source is closed before the paste +affectsmetoo

empathy

• Empathy needs to support OTR encryption +affectsmetoo

mozilla

• Firefox + Flash - Keyboard commands don't work when flash is selected +affectsmetoo

• Firefox Thunderbird Too many dictionaries available after installing a language +affectsmetoo

policy-kit

• No equivalent to polkit-gnome-authorization in policykit-1-gnome +affectsmetoo

sound effects

• gnome-volume-control missing ability to customize session sound effects theme +affectsmetoo

unity

• Resizing windows by grabbing window borders is difficult +affectsmetoo

• No way to disable notifications/notify-osd needs a "privacy mode" +affectsmetoo

usb-creator

• Startup Disk Creator requiring multiple authentications +affectsmetoo

• Format action wipes all partitions +affectsmetoo