It can be tempting to focus on a stock's current dividend yield, since the higher it is, the more money theoretically be flowing into your bank account. However, more often than not, higher yields carry greater risk. That's certainly the case with Targa Resources' (NYSE: TRGP) 7.8% payout, which is barely hanging on by a thread.TransCanada's (NYSE: TRP) lower payout of 3.9%, on the other hand, is as rock-solid as they come.