Airlines Offering Non-Stop Flights to Brazil from Various US Cities (as of August 2009)

—Miami—
To Sao Paulo:
TAM
AA
United
To Rio:
AA
TAM
To Salvador:
AA
To Recife:
AA

–Los Angeles–
To Sao Paulo:
Delta (Seasonal)

–Houston–
To Sao Paulo:
Continental
To Rio:
Continental

–Atlanta–
To Sao Paulo:
Delta
To Rio:
Delta
Northwest
To Fortaleza:
Delta (Seasonal)
To Recife:
Delta (Seasonal, Canceled?)

–Dallas–
To Sao Paulo:
AA

–Charlotte–
To Rio:
US Airways (Seasonal)

–Chicago–
To Sao Paulo:
United

–NYC–
To Sao Paulo:
Delta
United
Continental
TAM
AA
To Rio:
United
TAM

Some cheap deals can be found at www.atiflights.com.  This website includes connections to Gol which is not possible with Expedia and Priceline.  However, I would suggest flying on TAM rather than Gol.

For a multi-city vacation in Brazil, special deals can be had if you fly internationally with TAM out of Miami.