you have the Jetson like themed Disney designed Encounter restaurant atop the Theme Building that offers good views. Unfortunately the observation deck above is only open weekends. There is also the Proud Bird Restaurant on Aviation Blvd with landing views of traffic on 25s, however I really don't care for the food or service. You can also bring your own from some of the nearby fast food places and sit on the benches on top of the Imperial hill looking out across the airport.
, you have the 94th Aero Squadron Restaurant which is runway adjacent so you can catch close up GA
traffic. Down at LGB
you have the observation deck and restaurant above the historic terminal with open views of the tarmac and runways.
If you and your 2-year old are OK
being out in the sun for a few hours my top choice would be the Imperial Hill and if you want another airport the LGB