Dammit. Can't get in to the PRT 'cause of some bug.
I'm-a taking a look at those replays now, though Kain probably covered most everything.
EDIT: Alright, I'll add as I see 'em, and I'll try to avoid covering what Kain did, but unless I specifically contradict something he said, consider everything he said totally right. Most of my comments will be
very nitpicky/protoss-specific, so pay attention to the things Kain said first, as he got the big things. Don't let my comments on building placement distract your from his comments on scouting; they are not of equal value.
Game One, PvZ|
Alright. You're building at your ramp against a zerg. Good. I don't necessarily agree with your opening building placement, but... eh. There's a lot of personal preference involved there.
Your building timing is a little off because of the travel distance of your probes. As a
general rule - changes some based on the map - if you're building the first pylon at your ramp, send your probe out at 50 minerals. If your first gateway's at the ramp, send your probe there when you have 100 minerals.
Your assimilator is quite late (think 13 or 14 supply, generally), and your second pylon is early (which should be more ~15 or 16 supply).
Your chronoboost slipped early. If you're saving up to start pumping units, fine, but since you didn't scout, you wouldn't have any use for that...
Personally, I prefer cyber
before zealot, unless I
really really need that zealot. If you start your zealot with the first 100 minerals you get immediately after finishing the core, you should have almost exactly 125 minerals and enough gas as soon as the core finishes for your stalker.
At 4:20, you noticed your boost was starting to build up, so you began chronoing probes... but immediately got supply blocked. Pylons are your friends; they're what give you vision around your huge

ing bases to prevent drops and cheesey stuff.
4:53. You have two zealots and a sentry. He has four zerglings. You should be pressuring him. Generally speaking, I like to poke at an enemy's base with my first zealot and stalker and rally future zealots and stalkers to them. If I can do some damage, awesome! If I can't, hey, at least I forced him to build a spine and some more lings. Every pair of lings he makes is a drone that ain't mining.
Side-note on gateway timing: if you start a gateway when warpgate research is exactly half done, the two will finish at the same time.
6:30 - free overlord kill. Take it.
6:53, as your zealot slipped in, you saw he was making a tech building, but you didn't see what it was. Make sure you click on in-construction buildings when you scout (with a probe, not a zealot)! Also, your boost is full and you're sitting on resources.
Why obs first? Zerg have the least scary "cloaking" in the game. Unless it's a zerg who likes roach burrow, you're probably not gonna need obs for a while. And hell, you saw that his lair wasn't even done, so... really, no need.
And shit, I just noticed it now, but that first gate you made? Running off a lone pylon. Do you know how many brotoss have lost because they built their shit at their ramp and got their lone pylon sniped?
8:16 - excessive pylon placement? Maybe. But

yeah vision over your base! Still, why aren't you making units out of your robo? Or your warpgates?
After you saw he had a second base - which, really, no surprise - you just kinda... sat there. Didn't mass up units for an attack. Didn't take your own nautral. Didn't make a hard push for some key unit or bit of tech. Just sat there as he took the lead.
Good on you for getting colossus range. I'd probably prefer starting a colossus before range and then boosting the hell out of it (you're energy capped, remember) to compensate for the long research time.
As Kain said - and I want to re-emphasize this - your attack came at an utterly random time. You teched to colossus - even got a fast range upgrade - but your attack included zero colossii. You invested a ton in something that never saw any use. Part of that is because you kept using up your gas on other units/research, though. Don't be afraid to make more zealots if you need the gas for colossii.
Expand when you attack!
Bad forcefields let the lings down, though you caught roaches with 'em later at least. Would have liked to have seen guardian shields. Remember, stalkers in front get obliterated by lings. Stalkers are quite a bit faster than your other ground units until you get charge, so you have to keep them back behind the zealots yourself.
Part of the problem is that you were entirely on 1a. I split my control groups - zealots on one, stalker/sentry on 2 (until I get blink, then sentries go with the zealots), etc. Never, never, never just 1a in! Your fragile damage dealers will just walk in front of your beefy tanks and get destroyed. Immortals have the opposite problem, being slower and shorter range than the stalkers, they typically get stuck behind them (thus, I normally group them with my zealots on 1).
12:46 - okay, you won with two units left. Get another nexus up and R-U-N-N-O-F-T!
Don't forget to give your obs hotkeys (I like to use 8, 9, and 0). After making those early obs, you didn't really see
anything with them, including the zerg's oh-so-important spire. Your obs just kinda... hung out in your base while the zerg pumped out corruptors.