This wanting to be a better person, intellectually and morally; wanting to derive the most enjoyment from intellectual pursuits, appreciation of beauty in life; caring for people who deserve it and seeking out more people who deserve my affection.
That's my purpose in life. Not an exhaustive list, life being a process and all.
There is no ultimate meaning, no clear noble law to strive for, no nice conclusion to a well-lived life. Only whatever meaning you choose to make while you're living from day to day. Just be sure that you don't compromise and do something meaningless to you. You may die anytime so make sure you don't go with regrets.