Bouvier's Top 10 List (extended version):
1. A pair of fire fish (or two that appear to get along in the store) either purple or regular - cheap, easy, and peaceful. I did have one male kill another male though...
2. Yellow Headed Jawfish - really cool inexpensive fish with tons of personality (if you have a 3 inch + sand bed and no pistol shrimp and a FULLY covered tank). I think they watch you as much as you was them...
3. Pair or trio of fairy wrasse. On Live aquaria you can stumble on some more rare female fairy wrasse (I had to hold back many a time). It seems that females are rarely collected, but if you could have a nice big male Red Hooded Fairy Wrasse and two females (which I did before they found a crack in my cover - sob) the interaction and display the male puts on is worth the extra bucks. Pricey, but I'm a big fan.
4. 1 Atlantic Pygmy Angel. Cute, small, colorful, always moving/grazing and might not eat all of your coral - just some. I've actually had great luck with most dwarf angels not eating my coral.
5. 6 line wrasse. Cheap, colorful, easy, relatively peaceful. They'll prowl the rock for anything that moves, so watch out for your pod population...they may even eat bad flat worms and bristleworms.
6. Orchid Dottyback aka Fridmani Dottyback. No other fish is BRIGHT purple like this...mean as hell though.
7. If you don't have too many ornamental shrimps, hawkfish are cool - flame hawk, long nose, etc. They eat stuff (your small fish and pricey shrimp), but are fun to watch. They will sit on your coral.
8. Green Clown Goby. Nuff said - super cool fish. I will get many more in the future.
9. If you don't go down the Jawfish route (just look at a bluespotted jawfish and TRY not to buy it!!), I would consider a pinkbar goby paired with a tiger pistol shrimp - or whichever shrimp they are normally paired with. When this symbiotic relationship happens, the pistol shrimp/goby pair is freaking great. I have a 10 gallon dedicated to a "high finned red banded goby" paired with a randalls shrimp...going strong for 8 months now. The sand bed is an imporant detail here.
NOTE: I don't think that you could easily have both a goby/shrimp pair and a jawfish...jawfish freak easily and my pistol shrimps tear up the entire bottom of all my tanks.
10. Last, but not least, the bi-color blenny. These little guys are adorable, inexpensive, graze algae (just like your lawnmower).
I'll shut up now...