watch the fate series, I recommend starting from the oldest release of fate to the newest release of fate. Might last months or weeks depending on how you do it.
If you wanna experience the Fate Series, I wouldn't recommend watching the Animes.
VN is better as a first experience, with the UBW Series and Heaven Feels movies as later choices, completely ignoring DEEN Fate and watching Zero afterwards.
After that, I honestly do not think there is anything worth to watch in the series.
Instead you could watch Steins;Gate, Code Geass, the Digimon Series's, Angel Beats, Toriko, Assassination classroom, No Game No Life, Kill La Kill, Log Horizon, Elfen Lied, Gurren Lagann, Clannad and Clannad After Story, Melancholy of Haruhi Suzumiya, Higurashi No Naku Koro Ni, Lucky Star, Kino's Journey and Rozen Maiden, to name a few.