I you play metal, check out DiMarzio's Super Distortion. It gives a very high output and lots of midrange tone for distortion playing. Not very god for clean sound. Also (and my personal choice, but depends on your style), the Tone Zone is a great rock PU with great tone, great harmonics and output, very versatile. Another PU that I liked once when I played a friend's guitar is the Evolution; has a nice bright, cut-throuhg sound and harmonics, great for lead playing.