It's very common these days to have an engagement portrait session where your wedding photographer takes photos of the two of you. Sometimes the couple may use the pictures on their save-the-date cards or wedding website, but I think it's just nice to have them framed for your home - and your parents' homes.
Until you have kids you are probably not going to splurge on a photographer to take formal photos of you and it's really nice to have great pictures of you as a couple for your family albums.
Check out portfolios of wedding photographers and click through wedding blogs to see what other couples have done to capture great engagement photos. Splurge on a great outfit that you'll wear again and make him get dressed too, and go get your hair (and makeup) done. After the session, since you're all dressed up, make it date night or why not host an informal engagement party.