Would be great to run a poll, perhaps through surveymonkey.com or wedgies.com? In the meantime, why don't people list all options they use at the moment (which can become poll options later)?
Personally, as a practicing data scientist, I use the following (in order of preference):
- matplotlib in python (often in conjunction with the scikitlearn python library)
- D3 if i want to get really fancy and interactive
- ggplot2 in R (but only because Twitter's anomaly detection libraries are in R, would avoid if I could)
Note: I haven't used matlab since college, haha (numpy python library seems to have gutted matlab functionality?)