Do you follow them?
I did for our first anniversary, and maybe our second too, but I don't remember (E was still pretty new and I hardly remember our anniversary, whoops!)
Our third is in about a month, and the google tells me it's the leather anniversary. Although several things come to mind, I'm not sure he would be into them/not something he could tell people about (boom chicka! )
What did you give your DH for your third anniversary (or any anniversary!) Did you follow the traditional gift materials or just say Eff It?