I have drove in 49 out of 50 states (never been to Hawaii) and Illinois ranks the worst in my opinion. It’s like they ran out of asphalt and stopped doing any repairs 10 or 20 years ago.
To people not living in the U.S., feel free to complain about your country’s roads too.
Every list I’ve seen is completely different, but none of them have Illinois in the top 10 worst. The most consistent result I saw was Rhode Island being one of the top 3.