I'll add some sub-points:

1) AI risk is important

• ToolAI: http://lesswrong.com/lw/cze/reply_to_holden_on_tool_ai/
• Ng's position: "Worrying about AGI is like worrying about overpopulation on Mars"
• MIRI's actual effectiveness.
• item 1

2) Everybody should be vegan.

• Veganism is healthier than other diets (e.g. paleo, keto)
• Even if veganism is less healthy, it is still morally superior to other diets.

Other people have mentioned:

• Cryonics
• Relationships / PUA

Political topics:

• Free Market Policies
• Social Justice Movement
• The importance of environmentalism