For Her

One of my absolutely favorite ideas is having a custom drawing done of the bridal bouquet.  There are quite a few vendors on Etsy, but KJaneStudio is one of my favorites. 

Seriously stunning, I'd love to have one hanging on my wall.

Another thing for the walls would be a custom print of your wedding vows or readings from your wedding.
A lovely handwritten note or card is a lovely sentiment.  I have a few handwritten notes from Paul and I cherish every one of them.

For Him

A magazine subscription would be a hit with my guy, its like the gift that keeps on giving as it comes every month.  

Concert tickets if your budget allows
Books if your Mr. is a reading man
For him or her custom monogrammed stationary

And really, anything could be considered a paper gift if you give a gift certificate... or you give papers saying what you got them.  My gift was a new fridge, and I was handed the rebate papers.
Have a ton of money?  Go ahead and just get mortgage papers for your anniversary gift.