In defense of the gold dollar
So nobody likes the gold dollar except me; but I think it's a great coin, and I want to speak out for it.

The gold dollar is like pirate money
Pirates don't use bills, they have chests full of gold coins. Every time I use a gold dollar I pretend it's a doubloon. This never gets boring.

Gold dollars are cheaper to make
Unless you are a communist you will want to save the US Government money, which is what the gold coin was designed to do in the first place. Dollar bills only last about 18 months before they get so ratty they're pulled from circulation, while wheat pennies still turn up in the coin drawer after half a century. According to this presumably accurate PDF government document, switching from dollar bills to dollar coins would save the government $522 million a year.

And if you are a communist, you would be in favor of gold coins anyway, since Canada has them.

We are all spoiled children
People often complain that gold dollar sare too heavy, as though they risked a hernia taking the three steps between their segway and the escalator. But money is getting lighter all the time, thanks to inflation. If we consider how much a dollar bought in the 1860s, when bills were first printed, we can see that dimes were dollar coins. Everyone had pockets full of change. And now we have grown so soft and lazy that we balk at the idea of a coin to replace a bill that can't even buy a comic book. Really, we should constantly be replacing higher and bills with coins to keep pace with inflation.

Sacagawea herself
If we were putting people on coins because they are actually important to US History, Sacagawea would have no place on a coin. Lewis and Clark are obviously of greater historical importance than Sacagawea, and you could argue that her husband Charbonneau was as well. But reality has no part on coins, or Alexander wouldn't be wearing those horns; coins, like statues, are for myths and symbols. And Sacagawea is important mythologically. The more mythologically resonant Pocahontas might have been an even better choice for the female/Indian demographic here (if the Disney film hadn't made me hate her), but Sacagawea has the virtue that her original role was itself as a symbol--a pregnant woman with the Lewis and Clark expedition indicated that theirs was a peaceful mission. Sacagawea became a myth (the noble savage guiding civilization through the western wilderness) by being a myth (gentle maternity).

I propose John Henry for the two dollar coin, and, if we can swing it, Davy Crockett for the five dollar.

Sorry, Wild Bill Hickok and Betsy Ross. Better luck next coinage.

And what's so great about a dolar bill anyway? "What was it? A piece of paper crawling with germs." -Detour (1945).

N.B.: As you probably already know, the never-say-die treasury is trying for a dollar coin again, although this time it's another scheme to trick people with mental disorders into collecting things: a series of dollar coins with presidential portraits on them, in sequence, like state quarters. While it's pretty funny that Millard Fillmore and Richard Nixon will be appearing on coins (will Cleveland be on twice?), the Sacagawea will still get minted. So let's all support dollar coins in general and Sacagawea specifically! I'm not surehow to do that, but, you know, let's.