For new customers only, Google offers a Google Play Music Unlimited 4-Month Trial for free. That's tied with our mention from two weeks ago as a $40 savings and the best free trial period we've seen from Google Play Music. Google Play Music Unlimited allows you to access 35 million songs on-demand and ad-free and to download music to play offline.

Be sure to cancel the service before the trial ends; otherwise, you'll incur a $9.99 monthly fee.