well ok then!
to the OP, if you don't care about having shrimp in your tank, a pair of longnose hawkfish will provide hours of entertainment.
for vibrant color, hardiness and a really social fish, a royal gramma.
replace the blue tang with a kole tang.
a goby/pistol shrimp combo is great fun to watch. your kids would love it! gobys look like little frowny faced cartoon characters. they are SOOO cute!
if you have a cover on your tank (and you should!), a yellow coris wrasse would add a splash of yellow. beautiful fish and once they get over their shyness when first introduced, they are always out parading around and picking at the rocks for goodies.
stay away from the cute little inexpensive damsel fish you see all the time. they are extremely aggressive and will cause havoc in a peaceful tank.
again, go to liveaquaria.com and you can narrow your search down by first looking at the "beginner fish" category. lots of good ideas there. you will want to stay away from anything that requires even "moderate" care as opposed to "easy". the last thing you want is to get a difficult-to-care-for fish that might not survive when you have little kiddos.
all of the fish i suggested, i have in my 75g dt, among others that i did not suggest because i don't think you're ready for them.

just my 2 cents.