HUI's report defines best as generating the highest revenue from visitors and it is in Strömstad that foreign visitors spend the most.
The report explains Strömstad's continued dominance in its location near the sea and its proximity to Norway.
Winter sport destination Åre in Jämtland came in second place and Tanum, just south of Strömstad on the west coast, came in third.
The report has mapped the industry across Sweden and concluded that Sweden remains "in many ways an unknown and unexploited tourist country" and argued that a continued positive development requires investment in new and existing attractions.
HUI forecasted that improved communications to and from Sweden, and continued successful marketing, will create a further 60,000 annual employment opportunities by 2010.
The report has been written on commission from the Swedish Trade Federation (Svensk Handel) and the Swedish Hotel and Restaurant Association (Sveriges Hotell- och Restaurangföretagare).
The industry reported a turnover of 252 billion kronor ($38 billion) in 2009 and employed 160,000 people on an annual basis, according to the tourism sector organisation Svensk turism.
The other municipalities on the report's list of top ten tourist destinations are: Malung-Sälen, Härjedalen, Älvdalen, Stockholm, Eda, Sotenäs and Arjeplog.