Colour I find that I'm drawn to pieces with flat colours. I prefer pieces with large areas of colour with little to no shading or rendering. As for the colour themselves, I either love very bright and saturated colours, or the opposite, muted colours.
Line I love thin clean lines. I also like lines that have a continuous feel to them, as if the artists had drawn the line continuously without lifting their pen.
Shape I find myself drawn to pieces with a strong sense of shape. I love pieces where I can quickly see the shapes behind the different element, even if it's the elements themselves are more complex, like a figure.