If you really want to keep the missus happy, there's no better way than to give her a great anniversary every year. It's a great way to show that you are happy to be with her, you love her as much or more than you did on your wedding day, and that she's at the top of your list of priorities.
Try these ideas to plan your anniversary perfectly with activities and gifts to make your day really special
Let's talk gifts first
There are a few universally perfect presents for women. Obviously, jewelry is a big one. You know how expensive the gift will have to be to keep your wife happy. Flowers are another universal with the rare exception of women with strong allergies to flowers. Finally, there is chocolate. You may not want to surprise her with a whole box if you know she's on a diet, but let her know that your anniversary is a cheat day. She deserves it, and the contraband is on you.
Next, let's talk venue
You may want to save travel for big years (multiples of 5), and international trips for even bigger years (multiples of 10). But try to do something special that you both enjoy each year. Remember to keep it romantic. Even if you both love 311, your anniversary may not be the right day for a concert. Try romantic comedy, a trip to a theater, or a fancy dinner at either a restaurant with rave reviews that you've both wanted to try, or an old favorite with sentimental meaning (you know, the one you proposed at or the one where you took her for your first nice meal out together).
Take the Day Off
Here are a few more ways to plan your anniversary and make the day extra special. Take off from work (assuming your anniversary falls on a workday). It shows she gets top priority. Cook for her (only if you actually can pull it off, there's no point in you both going hungry no matter how nice the gesture). Have a picnic lunch in the park (unless your anniversary is in the middle of winter). Take her somewhere special (that bridge where you had your first kiss, or the bakery you always used to meet at after work).
What Really Matters
The ideal anniversary celebrates the time you've already spent together and holds the promise of a lifetime to come. Tell her you love her all throughout the day. Hold hands. Look into each others eyes a lot. Even if it was a long year, making this day special can remind you both why you fell in love in the first place.