Hedges, hemlock, red tip, forsythia,. You could also put up a light willowwood fence. You just unroll it and attach it. Kind of like a really long matchstick blind turned sideways. Maybe you could pay for those plastic slats.

Or maybe you could offer to pay for a portion of the fence in order to get something less ugly, share the cost. That is the only way you will have a say.

"Hello neighbor! Good fences may make good neighbors, but ugly fences make unhappy neighbors. How about we pay for part of the fence if we choose something we can both live with?"