Leptastrea and Leptoseris are both encrusters that do well and adapt to many types of systems/placement. Leptastrea has a bit fluffier polyps while Leptoseris has a thinner flesh but absolutely amazing patterns and coloring.
The countless variety of Mushrooms and ease of care really makes them an attractive starter coral. Rhodactis, Discosoma, Rhicordea, yuma... Within those species exist nearly any color or combination of colors and patterns that one could ask for.
If you're set on Mushroom and Leather specimens. I would try Blastomussa. Nice puffy polyps and a few varieties to choose from. Duncanopsammia, aka Duncans, is another hardy LPS that has big beautiful polyps and a nice colony structure/shape.
Chalices are also a good place to start with LPS. A ton of variety and types.
What type of tank are you running or setting up?