The first thing that came to mind was double wedding ring, but it can be challenging. There is a simpler DWR that uses striped fabric, 2 circles sewn together with a square of batting with an arc of the striped fabric covering 1/4 of the diameter of the circle. Turn right side out using a little slit in the space that will be covered by the arcs of striped fabric, sew the circles together so that the striped fabric has seams at the corners of the square. It can also be done using lace. I forget what this type of quilt is called.
Bargellos are fairly easy to do. Heart quilts would be good for an anniversary. There are appliqued hearts and pieced heart blocks. One of the simpler pieced blocks would be a 9 patch with half circles that could be appliqued. Done in red and white, this could resemble the Norwegian pieced heart baskets.