AGNC Investments (AGNC 0.50%) pays an eye-popping dividend. At over 14%, it's nearly 10x higher than the S&P 500's dividend yield (currently 1.5%).However, as enticing as that payout might seem, income-focused investors are better off forgetting about the mortgage REIT. They'll likely make far more money in other high-yielding stocks, including MPLX (MPLX -0.25%). Here's why the 9.3%-yielding master limited partnership (MLP) is a better option for those seeking a strong total return (dividend income plus st ...