1st SACD Purchase

Along with the other suggestions made, in the classical vein I've been very impressed with the recent Reference Recordings(Fresh RR) SACDs with the Pittsburgh Symphony, particularly their Strauss and Shostakovich recordings.  Also, the San Francisco Symphony's Mahler cycle and other recordings are excellent.  And one you might have to look hard to find is a Harmonia Mundi recording of Manuel de Falla's Three-Cornered Hat suites and Nights in the Gardens of Spain (HMC 801606).

Gram parsons grievous angel.
Bob dylan desire
I have them both on cd, vinyl, SACD and stream HQ tidal
SACD best for those albums... Been picking up rolling stones sacd from that there auction site... Search for dsd as people sometimes dont list as SACD so less bidders

One thing that I have found vis-a-vis  CD vs SACD vs High-Res (streaming or on Blu-Ray or Audio DVD) is that it's not so much the resolution that determines SQ but rather the care put into the mastering that matters. Here's an example: 
I have the RCA Red Seal  recording of Prokofiev's "Lt. Kiji" with Reiner/Chicago Symphony.  on three formats: vinyl. JVC XRCD (Red Book). and on BMG/RCA SACD. Both the XRCD and the vinyl sound BETTER than BMG's SACD remastering!  In fact it is one of the best sounding reissues I've ever encountered. The BMG version is dual layer and when I compare the CD layer of the BMG with the JVC XRCD, I'm gobsmacked at how much better the XRCD sounds!

I am also a McIntosh guy and SACD user.  I love the format, but getting music across a wide variety of genres is tough.  If you like jazz at all, Time Out by Dave Brubeck shows of what amazing sound can be had.

Dire Straights is also known for amazing recording quality, particularly Brother in Arms.

Food Luck in your journey!

Mike Oldfield -Tubular Bells, or Pink Floyd - Dark Side of the Moon.