What are the best use cases of AI you've found so far, or where has AI made the biggest difference in your daily work?

I use microsoft copilot to summarise all my unread emails n suggest what actions to be taken for those urgent ones requiring my attention. Super handy!

The lowest barrier to entry is using AI to help your writing and to remove writer's block.  It is so useful to ensure you don't have "attitude" in your writing and target the tone and voice for the intended audience.  The second easy use case is meeting notes summarized with AI.  The third is loading several doc in and using AI to summarize it.  My next step is to build some automation with an agent. 

Extracting data from faxes and loading the data into the enterprise system, structuring unstructed data, content development, webpage mockups using Lovable for sure, and being able to understand language (act as a medical doctor with 25 years of experience...does this physician note indicate the patient has osteoarthritis?)

I use it for a lot of curation of content. I'll write the first draft and then use Gemini to refine it.

But the killr use case I've found has been for coding MVP apps. I've used Loveable to create a fully funcitonal MVP platform that can be used with client facing work. It's not perfect and it has more tech debt than a box of ipod shuffles, but it's good enough to get the concept off the ground.

I prefer writing with Claude than my own writing, so that's definitely one.
I've built a number of automations using n8n that help me get my work done - filtering email, writing weekly updates, preparing monthly investor summaries. 
Analyzing data is something we do regularly with AI. I've built a custom GPT that takes an export of our wins / losses from Salesforce and allows me or the team to query them with AI. 
Doing research with AI as well - AI is quick and complete.

I've used the voice feature of ChatGPT to help me build plans and organize thoughts.  For example I had it helped me build a plan for when our new CPTO joined Rewind, and helped me clearly explain my expectations for him in the role.

In my personal life I'm using it all the time. I find that using it constantly for personal projects helps inspire me for different ways to use it at work.