I think Monster's better speaker cables are outstanding value, and the Z1 speaker cable is an outright steal compared to some of the more exotic cables out there. General sound is big, dynamic, expansive, and slightly on the warm side.
Monster is more hit or miss on the interconnects, and their products have a wider range of characteristics. The M950i, for example is fairly nice, well balanced, with a warm seductive midrange. The M850i is extremely warm, and can be quite pleasing on early digital recordings. The M550i Ive never heard, but the M350i seems to lack a little bit of integration and sound a little bit thinner and harsher than the others.
Yeah, there are better cables than Monster, and there is always the lates flavor of the month esoteric online cable company too. You just have to experiment to decide what you like best.
Monster's video cables are supposed to be quite good too, but I use Tributaries silver-series, which I generally prefer, other than their comparative stiffness.