In addition to Elite (which we used, and remain happy with 3 years later) and Pleasure Pools, both for gunite, we have a neighbor who used Regina Pools for a fiberglass job and they seem very happy with it, as well. We also got a quote from Anthony-Sylvan and it was lower in cost, but at the time their BBB rating was a B in MD, the others were an A or A+. Also, I just didn't like the sales process with A-S. Elite and Pleasure approached us like a custom home builder would. A-S was more like a mobile home salesman. That said, A-S does have many references locally who seem very pleased.
The good news is that you have a number of reputable builders to choose from in the Baltimore area. Just do your homework, follow all the typical rules when as you would hiring any home contractor, and research on TFP.