Your least favourite....

Well E.T. was famously terrible. But it was so terrible that nobody played it for more than a few minutes. I would therefore submit pong. It was also terrible, but it was so revolutionary that we still played it for hours despite it sucking so much, so it inflicted so much more terribleness into our young lives.

LF Activision game, for any platform.

I’m sure there are games I would have just hated, had I played them, like the many 007 games, but sticking to games I actually played, Pitfall! for the Atari 2600. Could not play it to save my life. Got past maybe the third obstacle. My brother, who was five years younger, finished it.
LF candy in a set of boxed chocolates.

Anything containing a nut of any kind. I like chocolate, and I like nuts; I just don’t like the two together (though possibly peanut M&Ms are an exception).

Least favorite event at the Summer Olympics?

Any long distance running. And it really irks me that we will be shown every step of the god damn boring-ass marathon but we are only shown the winning long jump/high jump/pole vault. If we’re lucky we might see 1 or 2 other contenders fail their last attempt before the winning jump.

Least favorite winter Olympic event

Figure skating and any other event that requires a judgement call. If a winner can’t be determined by an objective measurement it doesn’t belong in the Olympics. I don’t care if it is ‘pretty’.

Least favorite carbonated beverage?

Diet Pepsi. Or pretty much Diet anything.
Your Least Favorite Hanna-Barbara cartoon character?

Scrappy-doo.
Least favorite Schoolhouse Rock song.

Them Not So Dry Bones

YLF civil holiday in your country.

Thanksgiving, because I remember it as being horribly boring when I was a kid, and on top of that, I hated both turkey, and pumpkin pie. These days, I really like Tofurky, but I can have that on practically any holiday (we always buy a case in November, so we have them for holidays year-round).

I was even more bored on Thanksgiving than I was on Christmas (as a Jewish kid), because at least on Christmas, there was stuff to watch on TV.
YLF particular holiday (one year’s holiday-- it can be a holiday you like, just a disaster that year) you celebrated (or didn’t, if that’s why it was YLF).

My birthday from about year 7 to year 15. I’m a Labor Day baby, but it lands near my mother’s birthday and about 8 counsin’s birthdays. This meant the holiday was spent with the cousins over. Most were (are) male, with the females being to old to bother with me. It was burgers, hotdogs, a huge sheet cake and nobody for me to play or hang out with. And I dislike most cake. Yep, first world problems, but there it is.

Your least favorite holiday tradition and why.

My wife’s family celebrated Christmas on Christmas Eve, due to two Christmas morning crib deaths in the two generations before her. So we celebrate then, instead of Christmas morning, and I’ve never really liked it - I wanted to see my daughter’s face on Christmas morning when she saw the tree with all the packages. Instead we had to sneak around, and put them on the porch on Christmas Eve evening. Still fun, but…
Your Least Favorite pretzel.

Those little hard sticks. Seriously, WTF?
Your least favorite dessert.

Those delectable morsels? Seriously, W. . . just kidding. Pumpkin pie. Blech.
YLF day of the week.

Monday. Doesn’t everybody hate Mondays?

Least favorite month of the year?

February.
YLF pet that belongs to someone else.

The black cat that wanders all over my yard, sleeps in my flower beds, and makes extremely loud noises at odd hours.

YLF time to go to the supermarket.

After work. The supermarket is full of other people who have gone to the supermarket after work.

Least favorite pet you’ve ever owned?

Our dear, departed, retarded cat, and no, I’m not making that up. She had some kind of syndrome, diagnosed by the vet. I loved her, but wow, she was a lot of work. Every time we rearranged furniture, or something, it took her months to learn where things were, and in the meantime, she got lost and cried a lot. She also overate, and was very fat (when none of the other cats were). But, she was very affectionate, and a good pet for the reasons people have pets these days. If she’d had to earn her keep back in the days when cats had to be mousers, she wouldn’t have lasted a day.

Sorry, buddy.
YLF thread you ever participated in.

The insult-the-previous-poster thread. Just got tedious (no offense to the OP, whoever it was).

YLF vacation.

The one the only thing I remember about was that we were on the 11th floor of a hotel, and the elevators were out of commission. Yes, all of them. It was in Soviet Russia.
YLF medicine you ever had to take.