1. Create a basket full of Dad's (Insert Special Person's Day Here) favorite items - movie, food, gift cards, books, etc. Example: Create a "Movie Night" basket where you put in Dad's favorite movie, a box of popcorn & goodies.
2. Home Made Surprises - Make a collage of your favorite photos together or take advantage of many great deals on Snapfish, Shutterfly, etc. where they have 50% off photobooks during special occasions. Even making home made cards is enough to make that special person happy. Example: This past mother's day for both my mom and mother-in-law they received a home made gift I crocheted and for their card I had my daughter color on paper. I cut the paper into circles and attached with a string and on each circle I put one letter which spelt out "Happy Mother's Day". I started and ended the paper chain with each of my kid's hand prints. Now that is something they can cherish.
3. Bake! Cook! - Make their favorite meal and/or dessert! I think anyone can appreciate this gesture!
4. Take them out for supper. Now I am not always in favor of eating out, but there are great places such as Restaurant.com where you can buy giftcards at a reduced price for eating joints in your area. Example: You can buy a $25 giftcard for only $10. The catch is that you need to spend at least $37.50 at the qualifying restaurant when you order. You still are saving yourself a great deal and able to buy supper for everyone!
These are just a few ideas. Here are a few more that the previous suggestions were based off of: