I think the majority of Rush fans found him in the late 80s, early 90s -- before he ventured into the world of television. Those were his best years, IMO. His segments were fresh, unique and for the most part completely Politically Incorrect. He poked fun at everyone, but primarily the grifters and liars in positions of power or celebrity.
After the Clinton years, his show started to become less fresh and somewhat repetitive. Filling 3 talk radio hours for most people was impossible. He was able to do it without being scripted. He had his "stack of stuff" that he found to talk about, and whatever the callers added. I often found that the things he talked about were a week or more ahead of the Main Stream Media (another term I first heard on his show). That is, if the MSM ever covered it at all.
Every product he promoted, and every Liberal boycott he talked about, made money for those businesses. Listeners loved to put their money where his mouth was!

AM radio in the 80s was almost dead. Even newer radios were starting to be sold with only FM bands. Then Rush gave AM radio -- and talk radio specifically -- a defibrillator jolt! He was asked often why he stayed with AM, and he usually answered that it's because AM stayed with him. They supported what he was doing. Imagine trying to host a 3-hour talk show on any FM station. Not likely.
Three hours a day, 5 days a week, and special appearances in between. Yet, he was always prepared and able to recall names, dates and places with better ease than most people I know.
You know he was the best, because everyone on the left tried time after time to kick him off the air. You know you're successful when your detractors want you shut down.
I'm really thankful Trump awarded him the Presidential Medal of Freedom in front of the world at his State of the Union Address one year ago this month. He deserved that, and so much more for the good he did for the country.
Every time Big Tech says they don't have the ability to affect elections, think about how many people they've censored for trying to do just that, and how many wanted Rush to be silenced. There's a reason for that.