Inspired by main poll: if only one version of the one dollar denomination were to be, it should be the..
Neither. Lets just switch to debit or paypal. Not like we use either of them anyways
The bill. I don't carry many bills because I do most transactions with a credit card, but I do like to have at least 5 $1 bills along with at least 1 $5 and a few $10 bills. Most of the smaller ones are for tipping purposes, often to put together a $6-$8 tip for a breakfast for 3, sometimes a smaller tip for myself, but it's seldom $5 or $10 unless it's a more expensive meal.
I really don't feel like carrying around 6-8 fairly heavy $1 coins all the time. The bills are easy.
People who prefer to use cash rather than credit cards may have even more need for multiples of $1.
Ever try making it rain in a strip club with dollar coins? It's not pretty
What happened when you did it?
The coin, it's more durable, but should be plated with the same nickel alloy as the dime; brass tarnishes fast then looks ugly with barely readable denomination.
The much handled $1 bills are often faded and frayed.