After a lot of discussion in the development room, we thought it best to bring this to a public poll. With six options, this may look a lot like noise, but hopefully there's one or two stand-out favorites.
Here are all of the choices:
1. Thick Basic
2. Thick Square
3. Thick Round
4. Thin Basic
5. Thin Square
6. Thin Round
For whatever it's worth, as the one who made the sprites, Thick Basic and Thin Basic are my personal favorites. I'd be fine with either of them being chosen. For my money, the others are quite a bit behind those two.