Around 1986 or 1987 I was one of 2 pax on a 727, LGA to YYZ, American Airlines. I asked the FA, she said the plane had cargo and needed to be moved to YYZ for the morning run anyhow so they were going to run the flight no matter what.

Twice!
 

There were two occasions when I was the only passenger on a scheduled flight (there have been many many occasions when I was the only person in a light aircraft...)

Both these flights are fondly remembered.

The first one was from IPW (Ipswich, UK - now closed) to AMS, some time between 1986 and 1988. (The aircraft was a DO228) I was a regular on the route, and on first-name terms with the FA.

Her safety brief went something like:

"You know where everything is, don't you?"

The other flight was a turboprop flight from BRE to STN, on a long-gone airline called Air Bremen. The flight crew seemed to try their best to pretend they had a whole plane load of passengers...:

"Ladies and gentlemen, if you're sitting on the right you will see the Dutch North Sea islands"

"Ladies and gentlemen if you look to your left you will see Amsterdam Schiphol"

I played along with them and obediently moved from left to right back to left, depending on their announcements.

The FA must have told the captain about this when she took him his coffee... when she returned she invited me to go to the flight deck so that I could "get a better view"

Best of all, when the captain found out I was a private pilot he asked me to stay for the landing - this was long before 9/11, of course.

not really to myself but flew MSP-NRT about 4 days after the earthquake. Maybe 30 people on the whole 747

Once back in the '90s, STL to FYV on a Trans World Express Embraer turboprop. It was the last flight of the day, quiet but nothing exciting.

One time I was flying EVV to PIT on a USAir F28, last flight of the day. The nose gear failed (it quit turning) and everyone got off the plane and most passengers rebooked connections through another hub. In the meantime the ground crew figured out a breaker in the hydraulic unit on the nose gear failed. They switched it on but by this time there were only 6 or 8 of us left going to PIT. So we all sat in F, coach was empty.

DL 757 MCO to CVG
 

Sometime in 2005 my ex-GF and I were the only pax on a DL 757 from MCO to CVG. The crew outnumbered us 4:1.

Nice..

Having all the FAs onboard at your beck and call.. I guess sort of..

They were probably hanging out like passengers and tending to you on an as needed basis?..

oh one more, did a MR on Delta's inaugural BOS-LHR run, again, only about 35 people on the entire plane. Got to spread out over an entire row, had my food on one table, laptop on another, and my ipad on the 3rd. FA came back from BE and greeted and thanked all the Medallions for our business and gave us all the customs fast-track tickets that normally only BE gets.

I flew solo on a USAir 737 from BWI to CLT several years ago. I was indeed upgraded to F. The plane still needs to be there for the next flight from CLT so the airline wouldn't cancel just due to a low pax load.

SFO-LAX United Shuttle flight on Thanksgiving 2001. Myself + 1 family member, and 1 other person on board the 737. Our HKG-LAX flight had been canceled, so we had to go through SFO, otherwise that other passenger would have had the flight to himself.

I flew from Portland, OR to Chicago, IL about 15 years ago on a DC 10.
Only two of us in coach.
One in first class.
Closest I have come to flying solo.
And no, they did not upgrade us two coachers to First!

The only time I flew solo was in a Piper Warrior when I used to fly myself. :)
Those days are over. These days I let the commercial guys cart me around.

Did you ask?

Seems like an awful waste of space (quote from the movie Contact)? LOL!:D

This goes awhile back but I flew on McClain Airways from ORD to LAX and was the only passenger. Coming back we had a good amount of people on board.

God, I remember they operated from Terminal 4 because they couldn't get a domestic terminal gate.

Once planes were allowed to fly after 9/11, I remember being the only person in F with three people in Y. It was eerily quiet on that flight.

I flew SFO-SMF a few months ago by myself on a EMB-120. There was a non-rev pilot in row 6 and I had row 9 to myself. FA spent entire time talking with the extra pilot.

Funny!

A few months ago I was flying Southwest BUR - OAK...my flight was delayed 3 hours, but during that 3 hours there were 2 other BUR-OAK Southwest flights scheduled, so almost everyone switched to one of those.

When it came time to board, they didn't call A-B-C.. they said "okay, all 15 of you that didn't get on an earlier plane... time to board".

It felt so empty!