I am a big fan and was lucky enough to see him live on numerous occasions. He was always good, without fail. As for recommendations, there's a CD compilation of his two Muse albums, Lone Star Legend. A little less straightahead, but his playing on the Atlantic release Newmanism is some of his most intense on record. There's a nice date where he's paired with Clifford Jordan called Bluehead. One of his appearances at the Caravan of Dreams was released on a record called Texas Jazz Reunion (with James Clay, Hog Cooper and Cornell Dupree). Any and all of the High Note releases are worthwhile.
In my favorite live experience with David Newman, he was partnered with organist Leon Spencer at the Caravan of Dreams. The sets were electrifying, but apparently not recorded. In his last appearance at the Caravan, he led a band with the very young Roy Hargrove, Larry Willis, Walter Booker and Idris Muhammad--they were recording but it was never released.