I agree with Stanton. It needs to be something personal that shows how well you know him. One gift I really remember was when my spouse paid for me to go on a day trip on a boat around the coastline where we lived. We fished, swam and stopped for a picnic lunch. Another time she organised a weekend camping trip for the two of us so that I could go fishing in the mountains, despite the fact that I know she hates fishing and camping!
The anniversary gift you choose for your husband could be either a material item, or an experience. The former might include something to augment his favorite hobby or pastime, such as some new carriages and landscape details for his model train set, or those new trout fishing flies he has been dying to try out. Maybe your husband is an avid gardener and you could buy him a new plant. If you go for an experience, you could take him away to a relaxing destination for a long weekend, or just for the day. Or perhaps an evening dinner at a special restaurant – how about the one where you went on your first date, or where you got engaged?