You are probably aware that Valentines Day is approaching. So put your serious projects aside and think a bit about your beloved. LED heart will work just great for this :). Take a look at this Arduino controlled Charlieplexed LED heart project might be this will be exactly what you need to do.
It looks pretty simple, but there is some science in it. It uses 27 individually addressable LEDs and uses only 6 wires to control them. This is so called Charlieplexing wiring. When board is ready this is up to your imagination what to display. You can try out ready made software for this that is located here, or you can write your own and you don’t need to be tied to Arduino. Heart can be attached to any microcontroller that has 6 free digital pins start your show. Happy Valentines Day!