Google Music: When disliking a track, it automatically jumps to the next track.
Reddit - When going back to the list of items after viewing an item, the item gains dotted borders so you know which item was just clicked.
OS X - Searching in System Preferences highlights the relevant sections. The more relevant the section, the brighter the light will be.
Gigantt - When you estimate a task using free text you see a live preview of how the system is interpreting it.
/via Assaf Lavie
British Gas - iPhone app has a button to turn on the camera light when submitting a meter reading.
/via Jaik Dean
Pocket (iOS) - After copying a URL, opening the Pocket app will automatically prompt you to save the content.
/via Myles Tan