his VC, his ballets, and maybe Symphonies 4, 5, and 6, though they are little more strenuous.
The Brahms symphonies are more strenous, except for No. 2, and he wrote two of the greatest piano concertos and a great violin concerto. Mussorgsky's Pictures at an Exhibition, especially orchestrated by Ravel, is an absolute must. Berlioz's Symphonie fantastique is a favorite for many.
Then there are overtures by numerous composers such as Mozart, Beethoven, Rossini, Berlioz, Suppe, Auber, and of course, Wagner. OK, Mozart was a classical composers, but his overtures are great fun.