I don't think you can miss with any of them.
As has been noted, DLL and SLM will be closing sooner than Shuffle Along so seeing one of those might be recommended. Especially if there's a chance you'll be back in the city later.
DLL was wonderful. A smaller musical with a two person cast, quaint, intimate, melodic and charming. I'm glad I saw it.
SLM, with the beauty of its music and the absolute high level quality performances of its cast is IMO the "don't miss" of these first two though.
I saw DLL because I had pretty much seen all the Broadway musicals I had on my list at the time and had heard great things about it. Again, glad I saw it. But would give the nod to SLM.
Throw in SA though and it complicates the decision a bit. I loved the show, and didn't exactly find it the "mess" that some have called it on here….and I saw it early in previews too.
Nor was I confused by it.
I understand it might not be played out in the way some would like it, but I'm okay with that kind of storytelling on occasion. Even the rather long title suggests that there might be some storytelling behind it. Had it just been called Shuffle Along, then I would think it might lean more toward being a revival of sorts of said show. But the additional use of wording in the title makes me think that they will be telling a story. So I wasn't totally taken aback by it.
I think the theater star power this show has brought together on stage, the music, the performances, and that choreography (!) gives SLM a run for its money when it comes to choosing between the two. They are very different though, including the way the stories are "told." But I didn't find that to be the same level of hindrance in SA that others on here have noted.
Personal preferences acknowledged though.