Getting a gift that is personalized means you really thought about them and the gift you are giving them. What you get and personalize really depends on what type of person they are and where they are going. Consider getting monogramed wallets, bags, laptop cases, or luggage if they are entering the career world. Consider water bottles, backpacks, custom wood boxes that can help them store things or even bedding for someone going off to college. This is the time for you to show that you care about this person and their future. Names, monogramming, and even just an inside joke between the two of you will mean a lot as this person continues in life.
Life experiences can be the best gifts of all. If you are really close to someone that is graduating, consider getting them plane tickets, tickets to an event you know they will want to attend, classes to learn a new language, or just take them out for a night on the town. While in high school or college, the student probably did not have enough time or money to really live, so now is the time.
Honestly, cash is king. Every new graduate wants to receive cash and it is really easy to get and wrap. If you are not comfortable giving money, consider a gift card. Get a new grad a gift certificate for a store that sells things they will need for their dorm room, a Barnes and Noble or Amazon gift card for books, fast food cards for when cafeteria food does not cut it, or even a gift card to have business cards printed.
No matter what you give, if it comes from your heart and you purchase it with the person in mind, you will not go wrong.