Might I recommend bamboo? Right after you defoliate your side of the fence, plant a rear perimeter row (or line), of bamboo.
Why should, in this economy, you be forced into spending your life's savings on a PVC or galvanized, chain-link fence, when
with the help of mother nature, you can grow the best line of primary defense from your invading neighbor. Sure, it'll affect their
plans for overtaking your property with some nasty clinging vine, the tentacles which threaten your peace of mind, even unto your
property edge, you must show these neighbors that it is YOU who holds the upper hand here.
As I re-read your comment, I cannot help but think of "the little shop of horrors", the whole premise that a plant would ultimately
overtake you, drive you out to an internet site and pose a question that only a moron like myself would respond to. I've smoked so much
pot tonight that I feel like a laboratory monkey caught up in Charles Darwin's early experimentation with the very nature of mankind,
to gravitate toward hallucinogenic substances, and to do this without shame. If, to your neighbor you have been discounted for both
feelings and property rights, I can only hope that you arrive at an understanding that you DO have rights. I'd be going down to the local
nursery and getting some bamboo cuttings. You can always take the upper hand, not necessarily the high road but certainly the winning
position in the fight for the fence. I surely do hope that everything goes well for you. I had a few beers tonight. Cheers!