I myself like CO, since EWR is your 2nd preferred airport. Even with EWR's delays, since it is a major hub for CO, you'll have a choice of flights. And with the Chase CO MasterCard, you can earn many more miles. (That's how I earn many of mine! And if you're anywhere near a Shop Rite, you'll earn CO miles there too for grocery shopping!)

If you're stuck in Y, CO is one of the (very) few airlines that provide meals to Y domestically.

And since CO is part of SkyTeam, you can earn and redeem on many other airlines, including DL and NW!