I started my career laying out PCB's in the early 80's, a number of my boards are still flying today in several military aircraft, cant say which because I was under clearance at the time. Anyway, I started a company about 6 years ago and we sell equipment into a niche application, not a huge business, but keeps me busy. At that time, I did a survey of most of the cheaper layout applications at the time, and finally settled on Sprint-Layout 6.0. It doesn't have many bells or whistles, and it is totally manual, doesn't have autorouting, but does have clearance checking functionality. I believe it is the most powerful application versus price out there. (best value) I am still blown away by the fact that I can create a board in a few hours, email the gerbers overseas, and have prototype boards at my door in a few days at a cheap cost.
One of the limitations of Sprint Layout is its libraries, I have needed to tweak a number of them and create a bunch of my own. I was on the team that created the original IPC surface mount guidelines in the early 80's, so this is no big deal....
Since I am old school, I naturally comment that none of the programs I have seen can really assist a designer to create the optimum board construction, either in optimal routing, RF performance, design for optimal cost.