OP here. I am far far far from being an anal-type of person, but for some reason, this particular thing really gets to me. I'm not a fanatic about pulling every weed and mowing every blade of grass to a fine even point. You should see our backyard!
Due to restrictions regarding how much grass people can have on their property, most people save the grass for the backyard (which have walls around them)and do the xeroscaping in the front yard. My yard and my neighbor's yard are adjacent to each other (meaning no driveway to separate them). Our tree has not dropped one leaf yet. It is a late dropper and is always the first tree to bloom in the spring, which is why I love it so much! We have a huge Maple in the backyard and lots of other leafy shrubs, so we know the drill about blowing and mulching.
The problem with the front yard, is you can't suck up the leaves easily because the rocks get sucked up too and will eventually break the mulcher. So the leaves have to be blown to a corner where there aren't any as many rocks, which for us is on the other side of the house away from the front door. It takes a long time to blow them all over there and many trips do so because there are so many leaves and it takes time to get other leaves out of the bushes. Our tree's leaves get cleaned up right away.
And yes, the majority of winds here all blow Easterly, and not randomly. We had a windy afternoon today, so a good chunk of the neighbor's leaves are in our yard. If it rains tonight (It's overcast now) then the leaves will stick to the rocks. And for those who don't have a yard full of rocks, that many leaves in a very small yard do not just break down and full between the rocks. Some do, but the majority of them are visible and look bad. They also cause weeds to grow because debri and dust get trapped in between the rocks and and the weed-control ground cover. So it's looking like we'll need to pay a landscaper to remove all of the rocks and lay a new ground cover within the next year or two because weeds are now growing more and more in between the rocks.
I love fall, too! It's my favorite season! I just don't like when the neighbors get out of their car and carry in their pizzas while we are outside right in their view cleaning up their leaves. They can hear the blower on and off for a couple of hours, so I would think they'd realize it's not just a quick pick-up. At least offer to help, ya know?
So I will once again bite my tongue and clean up the leaves again this year. It's not a quick job though. It takes hours on at least two different days.
Oh, and whoever commented about my getting upset about a few leaves on the porch -- It's not a few leaves. It's a lot. That bush I mentioned where the leaves come from is as tall as the neighbor's house. The leaves are a constant annoyance in the spring & summer. The leaves are like plastic and have sharp needles on the leaf tips.
I guess I'd feel differently if I saw them just ONCE make an effort to clean up even some of their leaves. That would certainly change my perspective on things.
So, IDoDis, are you aware of my lovely wife's love for QVC? No? Well, she's gotten me addicted too.
Anyways, we clicked it on this morning because they're doing a Christmas wish list sorta thing, and guess what they had on? It made me think of you...
Worx TriVac 13 amp Multiple Speed Leaf Blower, Vacuum & Mulcher
It sucks up the leaves and mulches them for you. Plus, it's on a payment plan, so it'll only cost ya' $20 per month.

Maybe a Christmas present for you...or even your neighbor.
I still don't find anything wrong with simply mentioning the dilemna to your neighbors, though.
Clearly, folks here don't know you're sweet as pie and that you'd never approach your neighbor in a rude manner. Good luck, honey! Let me know if you get addicted to QVC.
Oh, and P.S.- We'd love to have you as a neighbor. And we'd invite you over all the time for yummy stuffs.
The OP mentioned their yards are rock/gravel so a non issue and likely why the neighbor doesn't care/do anything about it. They will break down into the rocks over time and there is no grass to kill.
Aww, thank you! I really am I nice person

This one thing just irks me for some reason. I guess I need to get over it. I'm already addicted to slickdeals.com, so I need to stay away from QVC!!! Your dinner tonight looks so good! Can you mail me a care package packed in dry ice??