[nategraves]

Personally: http://pentacular.com - Draw/paint a song. I think it's fun to play with.

Professionally: https://tailorbrands.com - Algorithmically designed logos and branding assets. It's great for side projects, inspiration, or any other situation where you want something quick and usable.

[mayank]

Tailorbrands is great! I'd love to see move than 6 designs though. Previewing the generated brand on various objects is a great idea!

[jbpetersen]

Some examples for tailorbrands that don't require interaction would be nice.

[Narretz]

pentacular seems fun, but it's a bit too unpredictable for my taste.

[nkg]

painting the song is actually fun! ^^