I think you'd like these violin and piano pieces:
Beethoven Violin Sonatas # 5 ("Spring Sonata") and 9 ("Kreutzer Sonata")
Mozart Piano Sonatas - if you buy a set of all of them, I guarantee you'll love listening to them whenever you're relaxing. If you don't want to shell out however much it costs for the set, just get a CD with a few of them. My favorite is Sonata #9 In D, KV 311 played by Eschenbach.
Bach Double Violin Concerto in D minor
The 4th movement of Cesar Franck's Violin Sonata is very famous and very beautiful.
Also, if you like simpler-sounding textures I'd recommend getting a couple of string quartet recordings, like Mozart or Haydn:
Haydn: String Quartet #62 In C, Op. 76/3, H 3/77, "Emperor" - the second movement of this is really pretty
Mozart String Quartet no 14 in G major, K 387 "Spring" and String Quartet no 15 in D minor, K 421