XVictoryX on 05 November 2015
No need to watch all of it cause some are just spin-off or had remakes.
It's okay to only watch these four. Most of them answered "Fate Zero" because it is the prequel of the first Fate/Stay Night(I'd rather you not watch this) cause it has a remake called "Fate/Stay Night: Unlimited Blade Works" which is a lot better in animation. Fate Zero exceeds all of the Fate Series really high. It is highly recommended you watch it for last and so I prefer you watch it in this order:
1. Fate/stay night: Unlimited Blade Works (TV)
2. Fate/stay night: Unlimited Blade Works (TV) 2nd Season
3. Fate/Zero
4. Fate/Zero 2
