I got on my soapbox here recently about the issue of prostitution. What got me riled up was casual nonempathic comments about degradation of people and statements of " fact" about the issue that oversimplified it. When I read some articles to double check my stance about the issue common assumptions were glaringly wrong, I posted one link and I don't think anyone read that

The popular notion that science and religion are natural enemies.

Definitely the anti choice people. The other one would be "I don't use birth control because God plans my children thing" the stupidity of that makes my blood boil.

People saying that religion and science are both beliefs.

Literally anything revolving miracles, practices, difference in beliefs and mother Teresa xP
Plus anything about psychology, history and science that involves religion

Knowledge, or when people say they've come to it, but their "knowledge" is in fact arrived at through a really shaky process, relative to other reasonable possibilities.

How Star Wars sucks. I can stand on that soap box like Lenin all day about The Last Jedi

People not understanding taxes and how contributing to the welfare of everyone raises the country as a whole. Wage theft and the wealth gap, drives me to speak out!

Parents choosing religion OVER their own children! Grrrrr!

The list of what DOESN'T make me whip out my soapbox would be much shorter.
If I say "don't get me started", you should probably run.

Easier to answer what doesN'T. Religion espec. all things Islam, anti-civil-rights (anti-gun) efforts, anti-1A (anti-speech) efforts, anti-7A (anti-jury aka "tort reform" ) efforts, denial deceit and delusion about violent crimes in our country, USA warmongering foreign policy, anti-freedom (anti cannibas) efforts, climate change denial, anti-4A (illegal warrantless spying) efforts, SJW / antifa / third wave feminists nonsense, the insane level of wealth and income inequality -- on and on and on.

The weak.

There are probably a lot of overlapping opinions here so I'm just going to dive in since there are over 40 ahead of me.

Separation of church and state, inequality for women, LGBT, and people of color, politics(especially the cluster**** that was the 2016 election), dirty/murderous cops and the crooked legal systems that fails to find them guilty, white supremacists/ racists...

That's all I can think of now, I'm sure there are more.

Pollution
Throwaway culture
Treatment of animals in factory farms-go vegan
Racism, all the “isms” actually
Greed
DAF people

For profit healthcare

Unfortunately the people that wrote the constitution intended to separate church and state, over the years religion siding gets votes so the political entities started incorporating religious ideas in the doctrines. If you read careful back in history people like Ben Franklin did not want one god idea he thought many gods would be better to avoid the prejudice issues (example my religion is better than your bickering) Not exactly certain why they did not listen to Ben Franklin they could have saved many miss doing in our history if the congress would have listened back then. How many senseless deaths could have been avoided?

I am not sure of breaking out my soapbox... But lot of subjects irks me. The growing fanaticism and fundamentalism in the government. Injecting the religious venom and killing the innocence of the child. Games people play in Corporate world -
The total apathy towards society by many corporates and then camouflage the apathy with CSR. List goes on

Corrupt politicians

Depending how strong my mood is it can be hard to keep my mouth shut about the following:

"Adopt don't shop"
"It's all in how you raise them"(dogs)
"Cropped vs flopped" ears

So the worst for me is the topic of dogs with most people.
I hate being asked about dogs as if I'm an expert (which I'm not-know just enough to be an opinionated pita) when in a group of friends because editing my thoughts isn't easy in that regard.
Have to pep talk myself prior "I will not talk about dogs tonight x 100" and feel inordinately proud when able to avoid the topic.

Gmos..ignorance...and chemicals

any bullshit

The big one for me is when religionists, including New Agers, like to pretend they are at a 'higher' level because the guff they believe in. Just can't stand that pretentious nonsense, and I"ll let them know;

I find political language to be as substantial as impure wind. Shifting alliances or viewpoints simply to gain votes based on a mandate that they have little or no intention keeping, kind of sums it up for me. In nearly every industry with which I am familiar employees undergo an annual performance review and are either eligible for promotion and or a pay rise. Why should politicians be exempt from annal or end of term assessments? Of course, this might result in a government based on meritocracy, that is, people who keep their promises and implement their pledges.

Billy Cart races

"Intelligent design". Candidates running on an eliminate-abortion platform. "Trickle-down" economics (give tax breaks to the "job creators" ). People who don't believe global warming is escalated by our industrial societies.