Arduino has opened up a completely new awareness of electronics for me. I've always been an analog guy, but after completing my desk fan project (http://www.chesterfamily.org/Projects/DeskFan/) and then discovering Arduino, I realized I could have made the desk fan perform better and for cheaper with an Arduino than I did with analog circuits. So desk fan v3 will be microcontroller driven. 
Ever since that revelation, my brain runs constantly, trying to think of more things I can use an Arduino for. For example, my chicken coop - I want to create an automatic door opener/closer and inside light that senses daylight and has a timer for additional flexibility. This is really easy to do with a microcontroller and can be 'customized", but analog circuits would only give me a very basic capability unless I make a very complicated circuit.