What was the biggest Eagles hit?  
Hotel California by far! What's your favorite?
That is a hard question.  Besides Hotel California. I'd say Take it Easy and Desperado.
Have you ever seen them in concert live? I would love to go!
No. I've never been that lucky.  I've seen some of their contemporaries, like CSN, but haven't been lucky enough to see the Eagles.
Do they still do live shows? My dad loves them and I would love to buy him tickets!
They did a Hell Freezes over tour a while back.  But that had to be back in like the 90's.
I wonder if they get played on Spotify or the radio often. They are super popular.
They still play them on all the classic rock stations.  You can always find Hotel California playing somewhere.
Do they still have their original members, like from when they started way back?
Haven't heard much lately. I think they are all mostly retired.