Realty Income Corporation (NYSE: O) touts itself as the "Monthly Dividend Company."  And indeed, it does pay a dividend every month: typically around the 15th.  Additionally, it has pretty consistently increased that monthly dividend.

As an REIT, it is required by law to pay out 90% of its income to its shareholders as dividends.  Most of this income comes from commercial and retail rent. 

At a current dividend rate of $0.14/share, that's a meaty $15 plus change per month with only about 109 shares.  Currently trading at around $28, that's an initial investment of approximately $3000. 

Buying stock in O beefs up a portfolio with a constant stream of dividends and ideally fits into a ROTH IRA or ROTH 401K.
Steady income you can withdraw when you retire, tax free!  Can't beat that! 

Highly recommended.
Again, not for the capital gain, but for that nice monthly flow of dividends.