Here's the issue with starter corals... They are easy to grow, they spread fast, and they are typically cheap. The reason they are this cheap is they tend to grow so fast that you start to consider them weeds in the tank and are then attempting to remove that coral. Personally I love the look of a large GSP colony or xenia pulsing in the flow like the rest of us. However I don't want a tank full of them either.
My starter corals were GSP, blue shrooms, brown palys, pink hammer, green nepthia, and a kenya tree. I have removed all of the GSP and am still attempting to remove the brown palys after 5 years... I gave away the blue shrooms but held onto the green nepthia, pink hammer, and kenya tree as I like them. Also the kenya tree made me some cash by selling cheap frags locally as it dropped babies.
My recommendation would be to look at what you want to d with the tank in the long run. This will help determine what to start with as far as corals go. If you want to have an SPS dominant tank, try starting with some easy LPS like hammers. If you want an LPS/Softie tank, start with a cool finger leather or maybe some shrooms isolated on a rock...
