Be someone's mentor. There is actually a funny story about this I'll have to add later.
Write the novel you know you have inside you.
Volunteer abroad for one month. Teach English in a foreign country.
Join a flash mob
Be complaint free for 30 days (acomplaintfreeworld.org)
Practice Gratitude for 21 days (keep a gratitude journal)
Party at South by Southwest
Take a picture every day for a year.
Donate platelets once a month for a year.
Pay for the order of the person behind me in the drive thru lane
Tip a server 100% of the bill
Give a panhandler all the money I am carrying.
Volunteer to take care of the USS Missouri
Become a Child Advocate
Do Random Acts of Kindness for every year I am alive in one day
Pick someone up from a bus stop and take them where they need to go.