A good graph creator?

Hey guys, I need to make a graph for a lab we did in Physics and since this is our report on it, it should be typed. I can't really find any, or at least any good ones, so I was wondering if there's a program that you guys personally use and enjoy?
Thanks.
It should be able to make accurate graphs with decimals, and be pretty straight forward to use. And a line graph, too.

http://www.educational-freeware.com/freeware/graph.aspx

How about this?

http://www.educational-freeware.com/freeware/graph.aspx

How about this?

I think that only works well with functions, from the looks of it.

Try searching for "Winplot".

If you're really advanced you could try Maple.

http://en.wikipedia.org/wiki/Maple_(software)