Chinese elms- they grew over 6 foot in less then 2 years, are adaptable to any soil and conditions.
Sorry to hear of your plight. Good luck!

Check the sex offender list for your neighborhood!

I have lots of privet
They grow fast and bushy

How about shades in the windows? Quicker than waiting for a plant to grow!

Oleanders

Oleanders don't appear to be hardy above zone 8...per Google.

I knew there was a reason why I wasn't growing them as they are so pretty.

I knew as soon as I seen this, that is was a neighbor issue, been there done that, I mentioned forsythia to you on another thread, but now that I see this I wanted to add that you ought to plant rose bushes in a row, the ones that have the largest thorns you can find, in case he tries to come any closer. we had a guy that lives diagonal from us that was standing outside of his door with a video camera, DH sees him while he was messing in the fridge (keep in mind we have a giant white pine tree, that is over our kitchen window) DH from the fridge, starts bobbing and weaving to try to see through the tree at this guy to see what he is doing and he jumped back in the house with the camera, now isn't that spooky?
I hate to keep the sun out of my house, but I really think mini blinds are the best thing invented, and they are inexpensive.

The first thing I'd do is call the police. This is against the law. Then I would plant something with thorns. What comes to mind is barberry or if he ever ventures into your yard and up to the window I'd plant pyracantha. It has the toughest and longest thorns I can think of. You could also invite his wife over to watch him peep into your windows. I'll bet he does it more when she's not home if he's married.

I have a row of REALLY SHARP-POINTY cacti...they don't grow so fast, but they do get everything that tries to come over the fences...