If you are trading options contracts, you should consider a number of factors. Two very simple components are commissions and liquidity. SPY (SPDR S&P 500 ETF) is one of the most liquidly traded options. By liquid I mean that the difference the bid/ask price as a percentage of the value of the option is small (this evaluation only pertains to out of the money options). Small would likely mean less than one or two percent. The narrower the bid/ask spread, the greater the likelihood that you will make a profitable trade. In addition, one should evaluate the cost of commissions when trading.