This is a very broad question. It all boils down to the expected return on investment from either. Some investments in real estate, especially commercial property have very lucrative returns and low risks which makes them better than stocks. Also, in a bear market, it is possible to collect a basket of blue chips yielding 10%+ in dividends. It all boils down to the best deals you have on a table and the depth of your pocket. Follow the money...not the industry. The best way to decide is to bring two deals to the table, which you believe are within your budget and are the best in either form of investment. Then do your math. Sometimes real estate wins, sometimes stocks wins.
A successful man is not he who gets the best, it is he who makes the best from what he gets.