Scientific Graphing Programs

[Jeffery Haines]

Interested in using a scientific graphing program (other than PC version of 
Microsoft Excel 2000) which will perform regressional analysis, plot complex 
data, ANOVA, ANCOVA, etc.  Program should be user-friendly, flexible 
and reasonably priced.  Excel will not allow me to plot complex 
absorption/elution data due to the large number of variables. 

Any program suggestions, prices, opinions would be helpful for an 
undergrad biochemistry student.