His String quartet no. 9 is my favourite string quartet. The final movement is absolutely stunning and out rocks every rock artist. Listening to that reminds me of heavy metal guitarist strumming and then a high pitch bend.

String quartet 7 and 8 are also brilliant

Other great quartet are Beethoven opus 18 (hell every Beethoven quartet)
Haydn opus 76 (although every 68 quartet are enjoyable)
Mozart final 3 quartet + his Haydn quartet
Mendelssohn op 44
Schubert death of a maiden quartet