I'm looking for some relatively simple graphing software, but can't find any.

Given a table of points, x and y coordinates,
I can input a list of numbers manually, have points appear on a graph, it can draw a line of best fit, and tell me the lines' slope. I am sure such a freeware/shareware program exists, but am having excedding difficulty finding one. Can anyone recommend anything? Preferably with a simple user interface.