I don't think it's quite that simple. How long have you been married? Have you got kids/Can you get them looked after overnight? Do you want to go out or stay in on your anniversary? How much can you spend?
All of that said, many men are just as romantic as women, so being told that you have planned something will itself be exciting as he won't have to.
Get a small gift and dress differently, then do something that makes him feel younger.
Go to a Fairground, take him go-karting, etc. Then go for a meal (men do tend to like food to be included).
Alternatively, do somethng couply. You'd be surprised how many men don't mind being "forced" to go to a relaxing spa with their wife.