This leading REIT is still a reliable income investment.As the S&P 500 hovers near its all-time highs and looks historically expensive at more than 30 times earnings, it might seem like a bad time to go shopping for new stocks. But dig a bit deeper, you'll find plenty of undervalued stocks that still have a lot of upside potential.One such value play is Realty Income (O 0.83%), one of the world's top real estate investment trusts (REITs). Let's review the four reasons it's worth buying before 2025 ends. 1. ...