While I do love Diana Krall, there are several jazz combo artists and recordings I enjoy more, especially for the pianist.
Modern Jazz Quartet ivory-man John Lewis' spare style has really grown on me over the years, since I first encountered their recordings when I was a young man of 24. The Complete Last Concert is a great choice, imo.
Thelonius Monk's Dream is another favorite of mine.
Brubeck and Desmond's 1975: The Duets is another, as well as the full Quartet's Time Out, of course.
And here I've gone and stepped in it... how could I leave off Duke Ellington, Art Tatum, Oscar Peterson, Bill Evans, and quite a host of other keyboardists of various styles? From Corea (especially Return To Forever's Mothership Returns) to Jarrett to Bud Powell to Herbie Hancock? To a ton of others I'd usually rather hear than Krall, and are too numerous to mention.
The truly great players do more with four notes than she does so often with forty, is sorta my take, though I do love her, too. Her sultry, though range-limited voice and pretty face haven't hurt her career any, either. Let's face it. The music and dance.