Hmm interesting concept.
In the good category I'd put(teams I'd say overachieved their user base):
Ceska Rep-great team building
Slovensko-recently rose to the top rankings
Chile-maintained excellence as a true top team
Peru-ranking/americas performance
Columbia-ranking
Schweiz
In the underachieving I'd rather not point out too many, but Germany has disappointed of late, and neither the USA or Turkey have really live up to their potential.