A good 20 year anniversary gift for him would be a time capsule. Time capsules can be filled with a variety of items such as a calendar, cookbook, or picture frame. It is up to you to find the gift that suits both of you.
For example, if he likes to spend his time playing World of Warcraft, you could give him some old picture frames of characters that have passed on, or you could purchase a calendar so that he can look back at his life from birth to now. The best gifts are the ones that show that you are there for him every day, even if it means putting extra work in to get them to him.
If you decide to get him an old picture frames, make sure that you know what the contents are before you get them ready. This will prevent any disappointment when the actual gift arrives.
If you want to know what is inside of the old photo frames, you can ask your man to take a picture of himself at different times during the past two decades. Then take that picture and look for all of the pictures you can find where he is smiling. You will need to do a lot of searching, but you will have to keep looking until you find the right gift.
You can even buy old photo frames in bulk and sell them on eBay if you have the money. Many people who are on a budget are starting to turn to eBay as they can sometimes get a better price on some of the items.
No matter what you choose to give him for his anniversary, just make sure that you know what he will enjoy getting out of his old picture frames. If he doesn't care about what he gets out of them then that is perfectly fine, but if he does, you should know what he is getting before you get it to him.
If you know what kind of photos he likes to take, and how often he takes them, then you will have a better idea of what picture frames you will get. If he wants something classy like a calendar then go for it, but if you are a beginner and don't know what to get him, you will have to figure that out by giving him an old picture frame or two.
Once you figure out what he likes to get out of his pictures, write him a special note or an email letting him know what you have chosen. so that he knows what to expect from you.
The gift of picture frames is definitely a great gift to give to your husband on an anniversary because of how long they last. They will last you for the rest of his life.