My favorite thing to use ChatGPT for is a personal tutor. I've been able, for my own intellectual interest, to educate myself about some topics in math and CS that have so far eluded me. The descriptions it generates are better than anything I've found elsewhere and if it's not clear I can say things like "explain the above for an audience with a background in computer programming" and it will re-attempt the explanation.

Rather ironically I'm using ChatGPT to teach me about AI, explaining concepts like tensors and attention layers. It's a great way to make sure I'm in good with Roko's Basilisk since my AI-generated immortal soul will be able to cite my ChatGPT log as proof that I helped bring the Basilisk into existence.