The annual survey asks journalists to name those in the agency sector they have found impressive over the year. Brunswick leapt to top slot after coming fourth last year.
Citigate Dewe Rogerson came second, followed by Finsbury and Maitland, in third and fourth place.
FD, last year's top scorer, came joint fifth this year, alongside Bell Pottinger and Hudson Sandler.
MORI research director Janette Henderson said: 'A spontaneous response is a very accurate indication of someone's gut feelings about an organisation. It shows that the company is top of mind.'
This year's research has also found that PR agencies' standing overall among business and financial journalists has declined sharply in the last year.
Of the 37 journalists questioned, most said that in-house PROs were now a far more useful source of information than their counterparts in the agency sector.
Journalists said the top two sources of information were telephone conversations with company officials followed by contact with in-house PROs.
This contrasts sharply with 2001's findings as PR agencies, which topped that poll, could only make seventh place this year. Journalists listed articles in rival publications, news agencies and press releases all higher than PR agency contacts.