EWR-LAX 2pm Tuesday United
No one waiting at any of the counters (First or Economy)
Took 2 minutes to check in and another 2 minutes to have ID checked (twice) and pass through security
LAS-SFO 12pm Thursday United
At least 150 people waiting in the Economy line; 5 or so deep in the Elite line
Other airlines were closer to 20-50 deep in the economy line...lots of random full luggage checks going on
Took about 25 minutes to get to the gate
If you don't have elite status and have tot check in at the economy line, I would definitely get to the airport at least two hours in advance. Also, even if you are checking in at a short line, getting called for a random luggage search could really slow you down.