Brooklyn has Luis Rios, a rail-thin gray-bearded fellow who seemingly spends all hours of the day walking or jogging around Prospect Park.
Well, heck. I think you might have posted while I was dithering on my post.
Cleveland has This Guy:
I saw one of those billboards when I was in Cleveland earlier this year. I had no idea what it was about. 
There is no shortage of eccentric characters in San Francisco. Another one is Frank Chu, who spends most of his time walking around the city carrying incomprehensible signs about some kind of conspiracy between former US presidents and alien intelligences, who he claims owe him royalties because they have been broadcasting wildly successful films about him in other galaxies. It’s not clear if he actually believes this or if the whole thing is an elaborate piece of performance art, but he has been doing this for over 25 years. Some companies have rented space on his signs for advertisements.
My city of Topeka used to have Fred Phelps but he died several years ago. His congregation is still there picketing, but not as much as they used to. A number of the younger generation is abandoning the cult.
St. Louis is going through something of a dull spell but we still have “Mr. Gary” Boyd, who shows up at various events wearing a crown and carrying a scepter, interviewing people about nothing in particular. Somehow he convinced a local TV station to give him 30 minutes every Sunday as a community affairs program.
I heard that a gay-rights group bought the house across the street from Phelps’ “church”, and painted it in a rainbow theme.
A common billboard tag of his is “You know what I do.”
No, I DON’T know what you do, nor do I want to find out, thank you. These ambulance chasers sure love to sprinkle in double entendres into these things, don’t they-that Morgan & Morgan guy had one which said, “When you fall down, we stand up.” Of that I am sure, as I can hear the boing sound coming from your pants…
Tim Misny helps people get justice.
Philly’s got a few characters, including Jesus:
Another one I just remembered. Jesus. Jesus drives around in an old beat up station wagon, plastered with pretty much exactly what you’d expect. I haven’t seen him in a while, but he was a common sight for at least 30 years. You could find him driving about 10 mph through downtown just about every day.
And his car has loudspeakers
And his house…I can’t imagine having to live next door to that. It has to be awful. (sorry, tiktok is the only place I could find it.)
In the 1980s, there was a Jesus Is Lord Towing Service in Des Moines. You’d see this tow truck around town with “John 3:16” painted on the door, and “You pay what the Lord wants you to pay” as the price.
Now I wonder, does New York still have the “the rent is too damn high!” guy?
ETA: Nope, apparently he retired from politics over a decade ago.
We got some mental-case dipstick that looks like a scrawny Grizzly Adams and wears a big fur hat, year round. His schtick is to walk down the side of the road backwards, twirling and dancing like an addled Dead-Head.
I hate the guy, because I’m sure he’s gonna waltz into traffic in front of me and suicide on my front bumper.
But the Naked Cowboy is still going strong:
If graffiti counts, then I’ll offer the Listen Bird. A simple outline of a bird, with a voice balloon saying, “Listen.” He started decorating Edmonton surfaces starting in about 2003. I was living in Edmonton shortly after that, and passed by a few Listen Birds on my walk to the supermarket.
Eventually, the Listen Bird migrated to other Canadian cities, and he’s been spotted in Montreal, Toronto, and a few others. He got a larger vocabulary, too.
More info, and plenty of examples from Toronto here:
Wild Bill Nelson of Wasilla, Alaska, ended up with more signs, purely because he drove bigger vehicles. But the theme of his signs touched only tangentially on religion, chiefly references to the afterlife: “All lawyers should be in Hell !”
Wild Bill had several sign trucks, one with a toilet on top, some towing trailers so he could have (yes, of course) more signs. Most were long screeds about our judicial system, though some were more pithy. (e.g. “Lawyers suck !”) He would drive slowly through parking lots where the most people could see, or cruise past the courthouse in nearby Palmer.
Everyone in the area knew Wild Bill, and he would talk to anybody. When he died in 2004, the area became just a tiny bit less unique.