Can someone recommend a few Joni Michell albums?

While "Blue" is her signature work it is "Hissing On The Summer Lawns" and "Hejira" that really challenge the listener. She stretches the boundaries of mere folk music and simple melody. Consciously artistic (she pushes herself to reinvent herself) as opposed to the confessional poet flower child bandwagon she hopped early in her career. "Court and Spark" is funny and lurid at the same time. If you had these four you wouldn't need any more.

Tarsando, good one really; sometimes I am just so dense! Sorry for missing it on the first go round.

All of the 1970's albums, for openers.

One idea is to start at the beginning - Song to a Seagull.  Just Joni and her guitar.  Unfortunately, it's poorly recorded, but - in many ways - it's the most essential record she's made.  Blue, Hejira and Court, and Spark are all great, too.

Indeed Song to a Seagull is wonderful music. Agree with Martykl on the sound quality. We can blame David Crosby for that (-: If forced to live with only 3, I would likely chose Ladies, For the Roses, and Hejira. But I'm glad I get to keep Blue, Seagull, and Court. As much as I like all of these, I am sitting on a sealed copy of Hissing that I haven't opened for years. I can be strange like that.