You’re right about The Eagles.
The Eagles’ uniqueness was their “California” sound-—reminiscent of, yet different from the great Beach Boys.
I don't think the Eagles sound at all like the Beach Boys, who came later. I actually think they sound more like the Rays--remember Daddy Cool and Tippity Top?. Nonetheless, they were solid singers, and I haven't heard an Eagles song that I dislike. Here are a couple of my favorites: