FWIW, there's a MyTSA app for iPhone & Android that estimates delays, and http://www.whatsbusy.com/airport can also give you a delay heads up.
In my experience flying domestically & internationally every month for the past 6 months, plan to get there 2 hours early for domestic, and 3 hours before for international, and you'll make it on time. This also depends greatly on the time of your flight and the airport, as both have peak times. When flying early, there is no rush. Red-eye, it can be stressful as some people are trying to make the last flight. When flying at more "convenient" times, expect the abbatoir line.
And when you have to make connections and they may be the last flights of the day, remember that the super-cheap internet-deal ticket you got probably does not include any refunds for delays. Certain airports are _constantly_ delayed, so check all your connecting airports and the connection times before you buy.
In my experience flying domestically & internationally every month for the past 6 months, plan to get there 2 hours early for domestic, and 3 hours before for international, and you'll make it on time. This also depends greatly on the time of your flight and the airport, as both have peak times. When flying early, there is no rush. Red-eye, it can be stressful as some people are trying to make the last flight. When flying at more "convenient" times, expect the abbatoir line.
And when you have to make connections and they may be the last flights of the day, remember that the super-cheap internet-deal ticket you got probably does not include any refunds for delays. Certain airports are _constantly_ delayed, so check all your connecting airports and the connection times before you buy.