I had to decide on which DI framework to use on a small front end WPF application that I worked on at a job last year (the app had a lot of singleton classes that were impossible to unit test hence why I needed to introduce a DI framework). I'd come from a job where larger framework choices had been made years prior by senior developers and their framework of choice at the time was Microsoft's Unity so that was what I had worked with for ~5 years. After a week or so of research and deliberation I decided to go with Autofac and found it to be really easy to set up and use. For me it hit the sweet spot between built in functionality and performance.
It works just as well in Core. As such, it's usually the first package I install in a new Core project.