What makes a real estate purchase a good investment?

[Matt Gorman]

I've been looking at real estate rental investment and I'm wondering what people think a good investment is.  If I made a purchase and only broke even after 20 years, meaning that I never recorded any actual taxable income but the property is completely debt free after 20 years, is that a highly desireable situation?  Or is it a safe bet, if I'm smart about it, to assume that I should look for deals (single family) that allow me to show $500/month of income after all expenses and the reserve?  

How many months/years should I plan for to get my initial $ investment returned?

Thanks much!

Matt