Problem with this 'best crossbow' question is there is no such thing as 'best.' We're all different shapes and sizes with different ideas on what we want, need and/or can afford. What is 'best' to one might be either lacking in quality, be uncomfortable to shoot, or be so pricey as to be out of the question for someone else. All brands/models will have their fans and detractors.
Having said that.... If I could suggest one brand to be a bit leery of, it would be Barnett. And I'm another Excalibur fan.