I'm turning 46 this year and will not give up my graphic tees! Of course, most of them are for my most casual days. There are a few that are more of a design than a message that I think are a little more versatile.
For years I was a DJ (and just returned to the airwaves this weekend after 10 years away!), so I have a weakness for concert tees, but only the girly cut ones now. I wear stuff like my Spoon, Wilco, and Old 97s shirts to go hiking or on weekends. I have a couple of Threadless ones, too.