I've emptied the gas lines before, and after turning the gas back on I was eventually able to re-light all my pilot lights, but this time I'm having no luck.

Does anyone know a good trick for that initial time you light your pilot lights after turning on the main gas line?

Thanks,
-Mark

You most likely have air trapped in the gas line.
You will have to open the gas line near the end, turn on the gas for a few minutes to let the gas push the air out.

A drip leg is often a good place to do this.

Agree but be very careful. The area must be well vented and no fire anywhere in the house while purging the line, no spark either. Even a light switch can make a spark

Thank you both, I added a Gas Ball Valve just near the Water Heater, and then I openned all the windows in the basement and let the air/gas run until I could definitely smell the gas. I then closed the valve and reconnected it to the water heater. After waiting 10 minutes for the air to clear I was able to light the pilot light within a few tries.

Thanks again.