Can someone recommend a few Joni Michell albums?

For the Roses, Hejira and, of course, Blue.

"Hissing of Summer Lawns", "Don Juan's Reckless Daughter", and "Court and Spark". "Miles of Aisles" (a live album that is essentially an overview of her earlier work). I recommend them all very highly.
She also made an appearance on a Herbie Hancock album called "Gershwin's World" which is beautiful and revelatory for the stark way it illustrates the changes to her voice and style that have happened since "For the Roses."

Blue is indeed widely regarded as her classic album.
It's available as a HDCD disc on the most recent remaster.
It's pretty much straight ahead Joni songwriter style with acoustic guitar and piano prominent.
It's reflective in mood and was apparently influential on Dylan prior to Blood On The Tracks............

"Miles of Aisles" is a double LP that has many of the most loved Joni songs, recorded in a live performance. The recording is a good one, and the crowd doesn't really interfere with the songs. The song "All I Want" on this LP is IMO the best version of that song she ever did. If I could keep only 1 Joni album, this would be it. There is one song that did not appear on any Joni LP, only on 45rpm single, called "Urge for Going", that is an absolute must-have song for Joni lovers. It is my favorite, out of all of her songs. A CD recently came out called "Joni Mitchell - Hits"(Reprise 9 46326-2) that has "Urge for Going" on it. It is the 1st song on the CD. I have that CD, and I also have an original pressing 45rpm vinyl single. Do not miss this song! It is her most beautiful work.

I second "Court and Spark". It's one of my all-time favorites. "Hissing of Summer Lawns" sounds about the same, but not quite as good.

Regards
Jim

My favourite is not one typically found on the must have list. It is "Mingus", yes, a tribute to the man. Very Jazzy.

All of the above recommendations are good ones and do not miss the little known 'Ladies of the Canyon', it is very mellow and a little jazzy, it is one of my favorites (even though I agree all the others mentioned are great too).

"Blue" and "Court And Spark" are probably her two most critically acclaimed and both are indicative of her general "style". They're both a great place to start. If you don't like those, you may not care for her more experimental stuff.

Kind of Blue and Miles in the Aisles--both great albums!

It's all about Blue.

You shouldn't forget "Turbulent Indigo"!

I have to second the choice of Hejira. The bass playing of the late Jaco Pastorius on that LP is incredible. Miles of Aisles w/Tom Scott's horns is also a great choice.

For simplicity it's best to divide Mitchell's work into three relatively distinct periods: the folkie, the jazzy years and the Larry Klein years. Her vocal artistry is the constant element throughout. "Blue" is generally considered the peak of the folkie period. A lot of people like "Court and Spark", but I prefer "Hejira" for the jazz period. The Larry Klein years is something of an extension of the jazz period, but the overall tone is more mature and relaxed. Try "Night Ride Home" or "Chalk Mark In A Rain Storm".

Mitchell always surrounds herself with first rate musicians (Jaco, Tom Scott, Larry Carlton, Pat Methenay, Joe Sample etc.) and sonically the albums are high quality studio multi-track, but not audiophile recordings.

My favorite is "Both Sides Now."

Viridian, it was a joke...both titles (now). Seriously speaking however,, I just listened to Blue for the first time in years and was reminded that "Carey" and "A Case of You" are two of the finest songs ever written. I also think the For the Roses album is up there with her best.

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.

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.

Just buy the 68-79 box set. You can thank me later.

She really has a great body of work. If we stick we the original question, it's got to be Blue,  then  Court & Spark as two starters.
The passion from so many here on a variety of LPs says much about her depth as an artist. There aren't too many artists who have passionate fans of what others might call her 10th or 11th best album! She is absolutely a benchmark in female vocals, folk, rock & jazz. Cheers,
Spencer

I would take the approach of getting one from the seventies , one from the eighties , 90's .... ect  . then decide which era you like and get more from that era first . Her album Dreamland is sonically incredible .