This is a good stratagy for a 3vs3 or 2vs2 shared game. It's also good if there is a 15-20 minute no rush rule, since it takes a while to make everything. For a FFA or just 1v1, it probably can be changed to make all around defense. Here we go:

1. Make 10 scvs.
2. When 9th is done have it build supply depot.
3. When 10th is done have it do the same.
4. When 1st supply depot is done, have the scv build another.
5. When 2nd supply depot is done, have it build a barracks.
6. When 3rd supply depot (9th scv) is done, have it build another supply depot.
7. While this is building, start to make scvs for gas.
8. Start making gas until you've filled up every geyser in your area and have 2-3 scvs per geyser harvesting, also use the scvs who were build because they will be done building by the time the 2-4 scvs are done being made.
9. When this is done take a scv and make another command center in a suitable spot for a base.
10. Start building scvs.
11. Then when the building for this command center is around 1000/1500, start to get scvs the make refineries.
12. Do the same as in step 8.
13. Next start getting scvs for minerals until you hit about 30.
14. Then start making 10-12 scvs and put a little rally point past your barracks and supply depots.
15. Then when they are all done, have those scvs make factories, so you get 12 factories, leaving room for add-on on each.
16. If you use 10 scvs make two more factories when the 1st two finish. Otherwise, when the 1st two finish have them make one armory each.
17. If you use 10, make the next two guys who finish make the armories.
18. After, the next guy who finishes after that, have it make a starport.
19. As you finish the factories, make the add-ons. When the 1st add- on finishes, research siege mode.
20. If you want, when the first armory finishes, research the charon bootsers for golaiths.
21. Start upgrading vehicle plating and weapons until you reach lvl 3.
22. Next, take all available scvs, that were making factories, and start making a bunch of supply depots until you reach 200 supply (this can make you be broke for a while).
23. While this is going on, your scv should finish that starport, when this happens, have it build a science facility. This is only so you get make level 2 and level 3 upgrades.
24. Once you get this done, have all of your builder scvs mine minerals.
25. Now just start pumping out tanks in groups of 12. It costs 1800 minerals and 1200 crystals to make 12 tanks.
26. When you get about 36 tanks, it's a good idea, to make 1 or 2 groups of golaiths. If your allies have air defense covered good, then just proceed to make more tanks until you max out.
27. Fell free to make another expansion to get more gas, also feel free to make more scvs to mine more minerals.
28. Once you break through the defenses, about 72 tanks is impossible to stop. If you want 72 tanks, you can only make 56 scvs, and 72 tanks. This will max you out on supply.
29. As you tanks come out in groups of 12, put them at the choke point so anything that comes by is dead. A group of 36 tanks will stop almost anything. A group of 72 tanks, probably won't fit, but they could destroy everything. Also make sure you have a detector buy these tanks to stop those dark templars and ghosts who are very annoying.
30. When the time is right, attack. Most of the time, if you break through, you will destroy more building than your teamates. I've gotten about 175 buildings in 1 game that I can remember, and my allies had about 30-40 each. Make sure your teamates protect your tanks with air defense, unless you deside to make those groups of golaiths, then you can have your golaiths defend your tanks. You can have a 48 tanks, and 24 golaiths, 56 scvs, or anything close.

That's all have fun.

CreepColony's Opinion: If your opponents go mass air, like carriers or guardians, this attack won't work well.