Its not about the number of projects but quality of them.  Include projects, personal work and anything else that show your dexterity in different tasks.  One thing for certain, keep digital renderings to a minimum.  Those were the exact words from many of the principals who've interviewed me at firms I've interned in.  Unless you want to become the rendering guy, the real workplace involves more than fancy graphics.  Employers are more interested in the overall design concepts of your projects, your ability to think, knowledge to draw details, design skills etc.  I include everything from school projects, models, photography, paintings, built furniture etc in my portfolio.  It surprises me that in many cases I've gotten hired over my other classmates.  I'm not too pleased with most of my school projects.  Remember, they want to see what value you can bring to their firm.  There are waay too many skilled in using softwares or making photorealistic renderings etc.  Sell your unique skills to them.  It should be about what sets you apart from the dozens of applicants they receive.

Thanks for the comment! Though I am surprised that firms aren't as interested in digital work from the get-go. I feel ya in regard to school work. After the first part of my first semester in M.Arch, I can say I am only "sort of" proud of any project or exercise i've undertaken, but I guess the nature of the game is that you constantly have to be ready for the next project. Unfortunately, we are moving away from analog work already, and I would have liked to take on a few bigger projects since I am not particularly satisfied with the first few iterations. I suppose there is always photoshop, or I could take on my own projects over christmas break. Thanks!