What are some interesting classical recordings to share with my beloved?

My partner is a classically trained cellist. She hasn’t been able to touch her cello much in these past years (because life dealt us some unexpected twists). Yet, she still knows and adores her music! I, on the other hand, just know when I like the sounds of something and my tastes don’t veer very far from Holst’s The Planets.

Please suggest some classical recordings that will delight someone who knows her stuff. Don’t be shy about including any modern classical composers (i.e. Edmund Rubbra is a hit around here) and take a chance on some lesser known pieces.