I got this one - https://www.makeblock.com/mbot/ which is programmed using a Scratch fork. It was a little bit tricky to get connect at first in Linux, but seemed to work pretty well once I sorted that. It has got an ultrasound distance sensor and line following sensor.

I saw this recently - https://www.kickstarter.com/projects/petoi/bittle which I thought looked awesome, but a bit pricey for me at the moment. It seems to also have a graphical coding environment.