I'm a big fan of both groups. I don't even know where to begin. Steely Dan--when I listen to Reelin' in the Years, there is such a depth and maturity, it's incredible to me they were maybe 21 or 22 when they (Fagen and Becker) wrote it. I've asked myself many times, "HOW DID THEY DO THIS?" My Old School is probably my favorite song of theirs. (I love the line about California falling into the sea.) I have good memories of listening to their greatest hits double album on road trips. Aja is probably my favorite album, but I'm also partial to Gaucho. I saw them once in concert in the early Nineties. They were amazing--until they performed their solo work. (Walter Becker's was the worse of the two and really not listenable.) When it was time for them to sing Reelin' in the Years, they sang it really fast and totally threw it away--as if they just couldn't stand to perform it one more time. Still, it was a great concert.
Randomly, I love this part from Any Major Dude:
Any major dude with half a heart, surely will tell you my friend
Any minor world that breaks apart falls together again
I had the opportunity to see The Eagles a couple years ago when they were on tour with their History of the Eagles. They were phenomenal and quite militant about no cell phones allowed (which I appreciated since I've been to too many concerts where the people around me are holding their phones out in front of them the whole time). I don't think I ever realized what incredible song writers Henley and Frey were until sitting there, listening to them tell the stories behind the music and really listening to the stories within their songs.
On a side note, every time Joe Walsh joined them or had a solo, the crowd just lit up. He has charisma, he does.
If I had to choose one group over another, I think I'd have to go with Steely Dan just because they are so unique. There is something about their world weariness and cynicism that gives me comfort.