I really love what people at deviantART have done as smilies: They look really customized for their website (note that I don't have any relationship with them). Another good example is probably Skype's smilies.
Some smilies that I think are missing:
- :P (a real tongue not the current thing that has nothing related)
- D'OH
- ANGRY
- SLEEPY (very usefull for dev)
- LOVE (useful for relationship boards)
- :S (not meaning confused and not :| either)
- ANGEL (there is a devil, so there should be an angel)
- WHEW
- HAPPY (since there are many smiles actually, it's pretty similar so may be forget that one)
- BORED
- SMIRK
- NOD (an agreement nod)
- SHAKE (a disagreement head shake)
- FIGHT/PUNCH
- YES (thumb down)
- NO (thumb up)
- AGREE (hand shake)