The S&P 500 index offers a paltry 1.1% dividend yield. Realty Income is high yield and highly boringRealty Income's dividend yield is 5.3%. See the stocks »If you're a conservative dividend investor, Realty Income could be a cornerstone investment. That keeps pace with, or slightly exceeds, inflation, but slow and steady is the name of the game with Realty Income. Pfizer is a turnaround storyPharmaceutical giant Pfizer's dividend yield is 6.7%, the highest of this trio.