What was the absolute worst weather you’ve ever endured? For me, it was the freezing temperatures of South Korea during field maneuvers.

I've been exposed to three horrid weather conditions in my driving career.  The first was in a taxi going from the Amtrak station in Buffalo to the hotel downtown.  The fog was so thick, you couldn't see your finger in front of your face and it was a white-knuckle ride all the way.  We asked the driver how he managed to drive under those conditions and he said that it was like that very frequently and you learn to deal with it.  

The second was my driving back home from Long Island after a Christmas dinner with my family.  None of us looked out the window the entire time we were there and when we left and hot outside, there were 6+ inches of snow on the ground.  I had never driven in that much snow before, so I was nervous and drivers were very mindful of the conditions and were driving very carefully.  The worst part of the ride was that I had my parent and my sister's mother-in-law in the car with me.  Needless to say, there was plenty of "backseat" driving.  I couldn't wait for them to get out of the car.

The third was driving back from Virginia to Pennsylvania after my niece's college graduation.  The snow was coming down in sheets and blowing towards the car.  The wipers couldn't get the snow off the windshield fast enough and my brother-in-law refused to pull into a motel to wait it out until the snow let up.  You want to talk about nerve-wracking!  We were on a major highway and the semi trucks were passing us as though the sun was out and the road clear.  I don't think we went more than 15 mph because you couldn't see the taillights of the car in front of you.  

Everyone shivers when I tell them I've done a skydive, but I felt safer doing that than any of the other three situations I just mentioned.

Not reading through rest of your post,
Worst weather I saw, hopefully it wasn't really a tornado, but a really heavy rain with some tremendous windy that I remembered,
then didn't have any power for about a week after that!

The first one was the tornado on the 12th of May of last year.  The second one was the tornado on Memorial Day of last year, so basically back-to-back tornadoes.  Those were the only two times in my life where I had to go to the storm shelter.

The 12th of May tornado hit the town to the west of my town, passed north of my town, then hit the town to the northeast of my town before it crossed into Minnesota.

The Memorial Day tornado was moving toward my town but it dissipated just before reaching it.

That sounds scary.

I've had a few in my lifetime. While a fairly new resident of Dallas Texas, I had just started a new job which involved a lot of driving.  It was around noon and the sky suddenly went dark, not black but a dark green.  Many clouds were in the sky and the air was ominously still and quiet.  The sirens began sounding so I called my office, didn't really know what to do.  The person who answered said " I don't know what you are going to do but we are all in the basement on the south wall, a tornado is coming, go to the nearest 7-11 one get into their cooler."  I did just that, a tornado, a good distance away, passed by.  Very scary, after the all clear I was amazed at how quickly everything returned to normal, like nothing had happened.  I was shaken for a while. 

"Worst weather" is subjective.  I enjoy all kinds of weather.  If there are strong winds, I'm right out there enjoying them (unfortunately, this area is not very conducive to tornadoes).  Same goes for thunderstorms (I would have loved to have been a storm chaser in my younger days).  We just had epic snows that crippled a good portion of the area - and I thought they were neat (even without electricity).  Ok, I wasn't fond of the 115+ degree temperatures, but it was still neat. 

Cyclone in the Indian Ocean. Much damage to the ship. I thought it was fun.

I was indoors and safe and dry in an upper floor apartment, but in 1987 we had slow moving storm that produced several tornadoes and brought 10 inches of rain in 8 hours.  I had been in the underground garage around 9 pm during a tornado warning and it was completely dry. A couple hours later, after seeing that a nearby shopping mall had flooded, I decided to check the garage again. All the cars were bobbing around in several feet of water. Across the metro area, streets were completely flooded and people abandoned their cars. Basements flooded and some houses collapsed. Sewers and drainage ponds just couldn't cope with the amount of water. The next few days the temperatures were over 100F, my car was a total loss, and there wasn't a rental car to be had. 

I've been very lucky, blizzards are about the worst that I've had to deal with. The most difficult thing about storms (rain or snow) in the northeast are when the electricity goes out. That's not usually dangerous, just annoying.