DVDs
When was the last time you rented a physical movie? Remember Blockbuster and Redbox? Now, Netflix and Hulu and Amazon Prime are the new way to digitally watch all your favorite flicks, making both DVDs and DVD players obsolete.
Answering Machines
Just like landlines are no longer commonplace, neither is the old fashioned answering machine device. Now, all smartphones have the capability to check your voicemail on the spot. Remember the days of having to call your answering machine's number to check your messages while you're out of the house?