The best days of my life have been at the O.

The day I was married I had lunch there, then narrowly avoided getting hit by a Fifth Avenue bus.

Hours after my daughter was born I walked down to the O from Magee-Womens Hospital while she and my wife slept, and then put a chili dog in her crib. Officially, this was to give some baby-to-hot-dog proportion to my first snapshot of the girl, but let's be honest -- I also wanted her to join the cult.

"Hot dog" (hah-doe) was one of her first words.

Since its founding 49 years ago, the Original Hot Dog Shop has probably received more national recognition than any other existing Pittsburgh restaurant. (Only Primanti Bros., a brother-in-fries, has an argument.) Gourmet named it the fourth-best hot dog joint in the United States. In 2002 The New York Times said, "This is not just a great hot dog. This a great piece of meat."

It is a beloved and unique part of life in this city. So I think I'm speaking for lots of people when I say:

Thank you, Sydney Simon.

First some particulars. The signature O dog is a pork and beef mix. Silver Star Meats makes the natural casing dog according to a secret recipe that Mr. Simon, the O's co-founder, concocted.

The fries are No. 1 Idaho potatoes cooked once in peanut oil, allowed to cool and then fried again when ordered. This is the same method used in fancy French bistro cooking, except the O serves them in overflowing paper tubs to bustling and inebriated crowds at 2 a.m.

The wall menus are hand-painted by former art teacher Bob Russell. He has to change them every time they change prices or add another beer to the selection.

Sid Simon "never, ever sacrificed the quality of his stuff," said his daughter, Terry Campasano, who runs the place now with her brother Bruce. "It was always the same amount, never gypping the customers, always giving a good portion."

The Original -- called the "Dirty O" by some -- is also not for the faint of heart, especially during the late nights, when Pittsburgh police are often posted inside and out. This is clear even to the Simon family.

Mrs. Campasano, 54, started working there as a teenager in the late 1960s. "On the front lines of the O for 41 years. Oh my god. I need a medal."

Later, during the boom times for the O in the 1970s, when Pitt football was in its glory years, she said working there "crippled you mentally, physically and emotionally, but it was a blast."

Even bad memories of the O are good ones. I was eating there as usual one weekend in the mid-1980s with two high school friends, during one of those periodic Oakland crime cycles. A group of kids jumped us outside, punched me in the head and sent me to the Forbes Avenue sidewalk to look for my (nonexistent) money. One of my friends stayed to fight them off and the other ran away -- I remain close friends with one of them (guess which) to this day.

As a college graduation present, my parents gave me $1,500 to plan a trip to Europe. A year later, when the trip had not materialized and the money was gone, I thought about where the money went: pie-charting it out, I figured I blew most of it on repeated O dogs, fries, beer and Oakland punk rock shows. (Sorry, Ma.)

But this led to a career epiphany: realizing I had no understanding of finances, but could put away a lot of fried food, I decided I might have a future in the newspaper business.

Born Sept. 29, 1928, Sydney was the first child of David and Ida Simon, and grew up in the Hill District and East Liberty.

His father worked in the shipping department at Kaufmann's and his mother, who came to Pittsburgh from Lithuania at age 16, raised Sid, sister Rosalyn and brother Moe. (Years later while helping at an Original franchise in Plum, Ida would still jot down orders in Hebrew.)

Sid started working at a deli on Mellon Street in Highland Park while in high school at Peabody and stayed there until his early 30s, when owner Tubby Levine sold it. Sid and Moe decided to open their own place, modeled on the popular Station Street hot dog shop in East Liberty, and Moe found the empty storefront at Forbes and South Bouquet where the Original remains today. It opened in 1960, the same year Bill Mazeroski won the World Series at Forbes Field, one block away.

The shop started as just a counter serving hot dogs, burgers and fries, with change kept in a cigar box. Over time Mr. Simon became full owner of the place (after buying his brother's stake) and would later expand the space, adding more seating next door and upstairs, and more food choices (such as pizza) in an attempt to keep up with other restaurants around the college neighborhood.

(He would also change the neon sign outside, shortly after his wife Esther died in 2000: It then became "Essie's" Original Hot Dog Shop.)

Mr. Simon didn't only fiddle with the restaurant. At home in Churchill, he patented some 10 inventions of different kinds, and worked on a clothing line for the visually impaired.

"He fought a battle," his sister said on the phone from Washington, D.C. "His eyes were always bad from the time he was extremely young, and continuously got worse. He always said the worst thing that can happen to anybody is to lose his sight."

Mr. Simon was first diagnosed with cancer more than 20 years ago but, improbably, beat it repeatedly. It began in his esophagus, and over the years he would have surgeries to remove growths in his shoulder, arm, brain (twice) and liver (four times), his daughter said. He would also help others through their surgeries, including a liver transplant for Nate Keys, the husband of the shop's night manager, Joanne.

Sid Simon died from his long cancer battles on Nov. 8, at age 80.

"He was an amazing guy -- a poster child for cancer patients. He had three or four different types of cancers and beat the odds on all of them," one of his doctors, UPMC surgical oncologist Charles Brown, said. "He had an amazing tenacity and perseverance. ... He was fantastic. It was my privilege to take care of him."

"My brother was the cat with nine lives," his sister Rosalyn said. "That's how I always talked about him."

Somehow the O keeps surviving, despite living in the shadow of Oakland's two massive nonprofits, Pitt and UPMC.

How big is UPMC? The gargantuan size of the health care system -- the No. 2 employer in Pennsylvania -- never really hit me until they put their letters atop the U.S. Steel Tower, making them visible across the city, from the South Side to the Hill District to my house on the North Side. Looking at the sign day after day on the way to work, it started to remind me of something: the all-seeing eye of Sauron from the "Lord of the Rings" movies.

Given the huge growth of both UPMC and Pitt, that is a lot for a family business -- one nestled into a three-story Oakland apartment building it doesn't even own -- to contend with.

The O catered to students during its first decades, but with the loss of Pitt Stadium and the rise of student eating halls and debit cards, its market has lately reversed. Its biggest season is now the summer, when fanatics like me make the O a regular cultural stop, along the lines of visiting the Carnegie Museums or Schenley Park.

The owners are in no mood to pick a fight with their nonprofit neighbors, but do deny persistent rumors that Sid Simon's old hot dog shop will close. "They've been saying this place is sold since the day I started," Mrs. Campasano said.

"We're going to keep rocking and rolling -- using everything he taught us -- for as long as we're allowed to stay."