This anime is known for having some of the best music of any anime out! Not only that, it's also a love story – it's about the lives of Shuichi and Yuri, and how their relationship impacts on that.
If you're nervous about the yaoi aspect, don't worry – it's not graphic (PG only). In fact, this is a great introduction to the yaoi world!
The series takes you on an emotional journey with the characters, and the animation is simply beautiful. Give it a try!