smug 

Definition:  (adjective) Exhibiting or feeling great or offensive satisfaction with oneself or with one's situation; self-righteously complacent.  
Synonyms:  self-satisfied  
Usage:  On his face was the smug look of a toad breakfasting on fat marsh flies.  

complacent: too satisfied with yourself or with a situation, so that you do not feel that any change is necessary; showing or feeling complacency