Some topics are a guaranteed Groundhog day with the same arguments over and over again, for example:
- free market vs. regulations
- Bay Area housing issues
- Google's evilness, ad-based Internet economy
- Facebook's evilness, benefits of deleting one's account
- Apple's design decisions
- is Bitcoin a bubble or not
- holy wars between programming language camps
- any kind of US politics
- diversity in tech
I've learned some interesting perspectives from these discussions but they are mono-conversations that I try to avoid nowadays.