In March I had a three week work assignment in the Los Angeles area. My Sundays were free so one weekend I headed to LAX and took photos of the mid-afternoon arrivals. The planespotting at LAX is a lot of the same traffic day after day but the experience of it is always a blast. If you have a long layover in Los Angeles I highly recommend making a stop at the In-N-Out on Sepulveda Boulevard, grabbing a burger and fries, and watching the planes come in. You can do this by catching the Parking Spot parking shuttle (Sepulveda location). The Parking Spot is well aware of people doing this and they are happy to oblige. Hop on the bus and at the drop off point inside the garage, just head for the single door, you will be able to see In-N-Out through it.
If you have a bit more time, there is another spotting area called Imperial Hill that is just as great for spotting but does not have the In-N-Out (or restrooms).
Below are a few of the shots I was able to get while at LAX. It really is a fun place to watch really large airplanes land.