I subscribe to the Stock Advisor, Hidden Gems, and Rulebreakers. All 3 are great newsletters that give 2 picks a month. I'm not sure about your risk tolerance. The Stock Advisor is the best because its picks are less risky than the other two sheets but still finds great stock picks that have a chance to explode over the course of 6 months to a year.
From what I've read about the income investor newsletter it's just a blue chip letter with stocks that pay good dividends. Nothing special but great for preservation of capital which is always a prudent idea.