One thing I like to tell people when they first start keeping shrimp, is to watch what you put in the tank. Any meds, water treatments or ferts should be shrimp friendly or you'll have a shrimpocalypse.
A really cool shrimp I have always liked, is the Bamboo/Flower shrimp. The get 2-3 inches big and are harmless. They also have great color. They do freak you out when they molt because the molt looks just like a dead bamboo shrimp lying on the bottom.
If you see a shrimp the same size as a bamboo shrimp but it is clear in color and called a whisker shrimp...run in the other direction. These shrimp are a nightmare. I bought 3 of them because the store told me they were good in a community tank...that wasn't the case. They ate 2 of my green neon tetra's before they found a new home in my piranha tank.