Neither should Philips. Damn cam-out design leads to easy stripping of the head.

Yeah, the Philip's-heads are all you need for screws.  The only thing I use flat-heads for is prying things open.  Frankly, the flat-head should probably be replaced with a mini-crowbar.  

Polygon or square heads are the nicest with a deep philips coming in a nice second.

I think Torx is the best one. Followed by Alan keys (though those have a tendency to strip if you don't use just the correct size)

I have never seen a square-head screw before...

Flathead sounds like a really offensive slur

@M.Yurizaki my frustration with allen screws is that there's a different size standard for US and UK and I only have US keys

@Energycore You mean "Standard" keys  

Well, that's what they call them here. Because you know, "ew, Metric system"

@M.Yurizaki I'm not gonna force all y'all to learn metric but if you guys want to leave in the past and have a much harder time doing conversions, then it's a free country I guess.

I like to claim some customary measurements are better. Like volume because it's in halves. And you know what else likes halves? Computers.

We need Triangle-head screws to take over - those would be the best...

@M.Yurizaki How many quarts in a gallon? Ok, 4 that one's easy. But how many fuild ounces on a gallon?

Also, how many inches are there in a mile? How many ounces is a ton, and how many a metric ton, and how many a short ton? How many cubic inches is a cubic foot?

Don't get into cubics. That's hard enough in metric

@M.Yurizaki that's my point! In metric the answers to all of these kinds of questions is always a power of 10. But you have to know the cube of 12 to measure cubic feet, there's 32000 ounces in a US ton, but 2240 in an Imperial ton, and 2204.64 in a metric ton.

Whereas if you ask me how many milimeters in a kilometer the answer's pretty clear: one million.

Google, please stop being a smartass.

I know that off the top of my head because all you need to do in order to make metric conversions is add or subtract zeros. In comparison, it's insanely hard to measure the mass of 10 fluid ounces of a liquid with 13 pounds per quart density.

By the way, that'll be 63360 inches in a mile.

@techstorm970 Square bits are actually common for wood working. I dont know why.