I listened to the Royal Scam not too long ago as well. My favourite Steely Dan album is probably Pretzel Logic though,
Gold, Easy Tiger and Cardinology are probably quite similar. Cold Roses, Jacksonville City Nights and Heartbreaker are perhaps a bit more country. 29 is mainly ballads. Rock n Roll is rocky as the name suggests and Love Is Hell is kind of a mix of them all.I like everything by Ryan Adams although I'd mostly recommend Love Is Hell, Heartbreaker and Cold Roses in that order if you don't have them yet.
I saw him in Edinburgh for my birthday last year. It was amazing. He played for more than three hours.