The answer is "it depends". There's a big difference between someone who is 5'6" and 6'0". Also, there's a difference for the type of bike and rider style. Your height, inseam, and arm length typically dictate your size requirements.
Here's a general road bike sizing guide: http://bicycling.about.com/od/howtor...ike_sizing.htm
(keep in mind, newer model road bikes are usually sized in centimeters and mountain bikes are sized in inches. A mountain bike usually will be a little smaller for the same person. 1 inch = 2.54cm.
For instance, I ride a 55cm road bike and a 19" mountain bike.

I'd recommend to get fitted and test drive a few models so you can feel the difference; a comfy and properly-fitted bike provides years of riding, the wrong size will be painful.

That said, a 17 inch mountain bike frame (which is common) would probably be a good starting frame for you to try out.
For the "universal", use the smallest person as the base size. As I mentioned, a bike that's too big will cause back pain.