Experimentation on living organisms. I don't believe the end justifies the means in any situation. Cutting corners to save money on raising and selling plants and animals, such as feeding them hormones, using pesticides and giving them the minimal requirements to live. No. Again, not justified, especially not for the sake of money
I won't gamble. I don't care how enticing the odds are, that's another line I just won't cross. I have never liked gambling even when I was a little girl I promised I'd never buy a scratch card or a lottery ticket. Never have.
I won't cheat on my spouse, not even a flirt with another man or woman. The very thought repulses me (that and the thought of being with another man or woman). I have been accused of it before by an ex and that was enough (even though I didn't do anything).
I can't say I won't lie. But I do avoid crossing that line wherever possible. We are human though, sometimes we lie without even realising it. I'm really working on that one to eliminate lying altogether. Lies just bring more trouble than it's worth, that one I learned the hard way from so many lies as a teenager (about where I was going, what I was doing, and overall distrust of my parents). I lie occasionally and I just can't help it when I think of the consequences of telling the truth (for example... I am lying to my parents when I say I have no interest in Islam). Which is a contradiction because lying is a sin in that religion, but they'd go mad if I told the truth and probably take an instant disliking to my best friend as a result! But most of the time it's just fear of short-term consequences of telling the truth. The long term consequences of lying far outweigh that but it's hard to remind yourself of that when you know what kind of short-term hit-storm you're in for if you say the truth.
I could go on but I'd start to annoy people so I'll leave it at that.