When I was shopping, the Parker was one that interested me. It felt good, which is important. Research led me to decide on an Excalibur. They are wider (except the new Matrix line) louder, and lack "sex appeal" being old school. they are also light, accurate, easy to work on, and very well built with a great warrenty. Parker has had some limb problems over the years, and that also played into my decision.
Whatever you buy, enjoy the word of crossbow shooting. It is fun.