Good graphical data analysis software (other than excel or gnumeric)?

I have several sets of data in CSV (comma separated values) format, and I’m looking for an intuitive application that will let me compare the sets to one another statistically (using a normal distribution or something similar). Maybe I’m just not experienced enough with excel, but the interface seems too clunky for what I want to do. Unfortunately, I don’t really have enough time to learn octave, Root or paw (unless someone has a really good tutorial), so any suggestions would be greatly appreciated. Thanks!

PS I’m primarily a mac person, but if the app is for windows or linux only, that’s fine too.