There is none. You have to pick your BO (build order) according to what you want to do. If you want to rush roaches then you'll have to get a gas earlier. If you want to just macro, gas might not be so important. If you are muta rushing, you'll need double gas. Look around and use google, you can find a lot out there. Here's my super macro BO though. Build drones until you have 250 minerals. Either do the extractor trick (hit 10/10, tell a drone to build an extractor, while it builds, build a drone, then cancel the extractor, then build an Overlord (OV). Or build an OV at 9, then build drones, there's some debate on which is better. Then tell your drone to go to your expo and build a hatchery. You should have 300 minerals by the time the drone gets there. Build a drone. Save up 100 minerals and build your second extractor. Then save up and build your spawning pool. From there, get ling speed (if you saturate the extractor as soon as it gets up, you should have the gas for it as soon as the spawning pool finishes. Then build queens, then power drones, making sure not to get supply blocked. You'll have a rockin econ but a lackluster army. If they do an early push, you should be able to scout it with either an OV or some lings (get lings somewhere in there) If they do push, throw down some spine crawlers and make some lings. It should be enough. Jesus that BO sucks (not mechanically, just how I wrote it, I should get an actual concrete BO, oh well)
Its pretty standard, but its worked well for me: 9 OL 13 Scout 14 Pool 15 Hatch 16 Extractor 16 OL 16 Queen 16+ Pump drones or lings depending on scouting, upgrade ling speed, throw up spine crawlers 22-25 lair... My BO changes based on my scouting, but it stays pretty standard up until the Queen
i like to get my gas before my pool, so i can get speed-lings asap so i can harass... sometimes winning the game.
I've found if I go a 14 pool, if I get my gas at 100 minerals (that is send the worker to build the gas when I have 100 min) and make a Spawning pool as soon as I get the minerals the timing is perfect.
how effective are speedlings for you guys? I find them to be pretty worthless against walled terran, which is 50% of my opponents. I almost always skip them and go for roaches.