As for not-Puerto Rico, and Lucha Underground, I highly suggest at the very least the Fenix feud; which is notably Grave Consequences, the Muertes return match w/ weapons, and the awesome title match in season 2. The Ivellise match is a YMMV highlight as well, since it's the best intergender stuff in Lucha Underground. Can't forget about the triple threat with Pentagon Jr. and Prince Puma as well! As well as the Ultima Lucha title match with Prince Puma. In order:
Grave Consequences
Muertes vs. Fenix No DQ
Muertes vs. Puma
Muertes vs. Ivellise
Muertes vs. Pentagon vs. Puma
Muertes vs. Fenix, season 2
Coupled with some vignettes can't hurt.