This is primarily a Monkees greatest hits album released in 1986 to honor the 20th anniversary of the TV show and spawned a reunion tour by Mickey, Peter, and Davy. It was the album that, along with the show's re-runs, made me a fan of the group. I was not even born when the show originally aired but was pretty much the perfect age in 1986 when the group had a huge resurgence in popularity because the show was being played on Nickelodeon and MTV almost constantly. It does also have a few new songs that feature just Mickey and Peter (Davy did not sing on any of the new songs because he did not think they were paid fairly, and Mike was still pretty bitter about the whole Monkees experience and pretty much-avoided anything to do with the anniversary and the reunion aside from making one appearance at one of the tours stops).
The album includes all of their major hits like Last Train to Clarksville, Daydream Believer, and Plesant Valley Sunday, as well as some of the more obscure songs like DW Washburn. The last three songs, Anytime, Anyplace, Anywhere, Kicks, and the song that got them back into the top 40, That Was Then, This is Now, are the only new songs on the album. They are not the only new songs that the trio of Mickey, Peter, and Davy put out around that time as there was another album "Pool It" that included new material, but did not do nearly as well as this album did.
Overall, it is a very good greatest-hits album. It is probably even more of a desired item now that three of the four members of the group have passed away, but whether you were a fan of the group in the 60s or became a fan after that, it is definitely a must-listen.