2 Immortal 2 Collossus All-In (vs. Zerg)
This guide includes two build orders. The first opens with Phoenixes to kill off scouting Overlords, thus preventing convenient Overseer scouting. These Phoenix also serve to pick off Drones that venture too far from Spore Crawlers, delaying the Zerg's production, and keeping him in the dark. Phoenix openers also tend to lull Zerg into a state of relaxed Droning, as these Protoss builds typically transition into a third base. The second the Overlords die, Protoss cuts right to the chase, pumping out Robotics units as quickly as possible for the earliest move-out timing. Another important difference between the two builds include Sentry and Force Field count, as the Stargate opener will have less gas available to invest in early Sentries, resulting in less energy in the final key fight.
 Anti-Muta Play
Mutalisk play is moderately popular in ZvP, and dealing with those mass Mutas is a common problem for Protoss players. Going for a 2 base all-in to try to kill the Zerg before or right as he gets Mutas is certainly a viable option but that is dodging the problem, rather than dealing with it. This page outlines how to play a long macro game against Mutas.
 Basic Information
Builds that blindly mass Sentries at the beginning are bad, particularly if the Zerg is going Mutalisks. Getting to 8-12 Sentries early game seems to be very common in PvZ, but it is often not a good idea, unless going for a quick 2 base all-in. Guardian Shield is great against the bounce attack of Mutas, but the Sentries are often going to get sniped quickly, ending up just as a huge waste of gas that could have been better spent on additional Stalkers and HT. Sentries are also ineffective against Infestor/Ling play, Baneling play (with Overlord drops, and any more than a moderate amount (like 4-6) will be a waste against early 2 base Hydralisk play. Start with 2-4 sentries (note this is starting with a FFE, so if you're Gate expanding you could use a few more) and only add more if you scout Roaches.