Graphing paper is pretty awesome, especially for drawing. Lined paper is best otherwise I think. Plain paper isn't good for much, as you really need lined paper to write, and graphing paper is better for diagrams or math.
I prefer Lined Paper because it is easier to write on because it has lines and a margin and it is easier to notice a mistake. Also, it looks a lot nicer written too. Plain Paper is better for drawing.
Unless I am doodling or drawing I use lined paper. To me it looks better and the lines keep you spaced right and in the margins when writing. I like using the larger spaced lined paper because it gives me more room to write.