For me, I worked in the video game industry for 7+ years. I also worked on the marketing side of things within technology. I used to keep it short and to the point. Something that was easy to read, yet communicated my skillset and what I had to offer to a potential organization.
Unfortunately, in the technology world, sometimes that is not enough. I had many agencies tell me that more was better. That I should be listing out all the multi-million dollar projects that I worked on and include details on what I had to offer. On top of that, trashing that catch-all resume and tailor each resume specifically to the job you want.
When I did that, I got hired. Since then, most agencies I've worked with ask for the same. They don't want simple easy resumes in my area because they are too vague. Technology specific hires are burning companies because they simply rushed the hiring process and really didn't know anything about the candidate they were bringing in.
But, that could just be my area.