I don't play the lottery, but it's fun to dream about what I'd do:
Pay the taxes, give 10% to our church and another 10% to other charities.
Pay off our mortgage, have a heated pool installed (my husband and I both have arthritis and it would be SO nice!) and some landscaping done. We love our little house that's just right for us, so we're staying put. We would definitely hire someone to take care of our yard...my husband hates it and only does it for me because I love living out in the country.
Purchase a home and a small boat on the bay so we have a place to vacation with our kids....like a family camp. Host a family reunion there every year.
Finish paying for college for our three college-student kids, offer to pay for our oldest son's grad school, and put away enough to pay for our two youngest boys' college.
Set aside house down payment funds for all six kids so we can help them get into their first home...I think it's important not to hand everything to them entirely.
Increase our Christmas budget. =)
Do ministry. We like to be generous and often we wish we had money to help people out. For example, the teenager across the street has a truck that doesn't run and he doesn't know how to fix it. His dad has never been in his life, and my husband would love to take this kid out to buy what he needs for the truck, and then help him to do the work. What a great opportunity to form a relationship and mentor a young person! These are the kinds of things we like to do whenever possible.
I would buy a new laptop computer and an iPad for my husband, so he can work on his book when he travels for work, and a large television for the man cave. And for me, a weekly massage for my aching muscles, a food processor, and some rugs for the house (we have wood floors and hardly any rugs). We're pretty simple people and don't need much, but it sure would be nice!