Component carries an analog audiovisual signal, the quality of which can be affected by the cable itself. HDMI carries a purely digital signal, meaning that no matter what, as long as it's working at all, the data will be the same on one end, as it is on the other.
In other words, HDMI.
Also note that because it data digitally, you don't need to shell out for "premium" HDMI cable. Don't be fooled by marketing from companies like Monster Cable: all HDMI cables carry the same digital signals, and there is no variance in quality. Go for the cheap stuff; it'll work just as well.