Shrimp gobies are awesome! I have a yellow watchman goby and love it. Full of personality. Of course, the shrimp goby/pistol shrimp symbiotic relationship is amazing as well. I would strogly recommend picking up a pistol shrimp as well. I have had my goby in a topless tank for almost four years with escape attempts. Infact, he hangs out on the bottom on in his den with the shrimp pretty much all of the time.
Some people are like slinkies...they serve no real purpose yet can still bring a smile to your face when you push them down the stairs!:p
Have a great day! Brian