I've only been listening to classical music for close to a year now. I find it to be very relaxing. I love the essentials like Beethoven, Mozart, and Bach. I've also gotten into Tchaikovsky (partly due to his epic contribution in V for Vendetta).
Most recently I've discovered "Love Dream" by Franz Liszt. For those unfamiliar with it, it is a beautiful piano piece. Not too complex but not simple either rather simply beautiful.
I'll take any suggestion but if you know of anything similar to "Love Dream" that would be grand.