Greetings,
Any watchman goby would be lovely, a pair with a pistal shrimp would be doubly lovely. Yellow watchmans are cute because the boy is yellow and the girl is often white or light grey. Pink spotted watchmans are also nice, I've had one for 3 years now, the only thing with this particular one is that he likes to play with my hermits and sometimes by playing, he ends up eating one or two...but he keeps the shells around his little cave as decorations.
Tiger goby is really neat, they will go around and sift your sand and they have lots of personality, I think more so than the yellow or pink spotteds.
Orange spotted blennies are really nice too and they have a most adorable face. My recognizes me and comes up to beg for food.
Lawn mower blennies are nice if you can get them to accept available foods, my particular lawn mower wouldn't eat for three weeks and after trying everything I can get, he started eating Brown nori sheets, he is so sweet that he will sit in my hand while I feed him and then he will use his hairy mouth to kiss my hand - I adore him! He only started eating mysis, formula one and two frozen, and pellets after more than a year in my tank, so do be careful and select a fish that is eating well.
Starry blennies are really pretty and they change colors often, like going from brown to maroon with white spots and patterns, to a light tan...
Bicolor blennies are nice also and they help with eating hair algae - well, mine does eat them on a fairly consistant basis.
I have alll the above creatures currently so if you have specific questions about any of them, just ask!
Oh, another one that is neat is the Yasha Hase goby with pistol shrimp. I had mine for three years and saw him only when I feed...so, for the price you pay, I would rank him on the bottom of the list.