What’s your favourite computer sound?… the sound of an incoming email or message, the sending of one. Maybe it's the sound of the trash being emptied, or something else?

The sound of the trash/bin being emptied on my new macbook is new to me. I really like it. It sounds to me like thin glass or icicles being gently shattered, or crackly paper being torn. I have chosen a different sound for incoming emails, that I find less distracting but nonetheless present.