Although prospective customers view most banks positively after experiencing their sites, Wachovia got a brand boost nearly twice the industry average of 35 percent, Keynote said. The online experience also made Wachovia the most successful bank in terms of online customer acquisition.

National City placed second in the rankings based on the appeal of its overall site design and organization, as well as the ease with which a new customer can open an account online, according to the study. Bank of America, which has placed in the top echelon in all Keynote banking studies, was bolstered by its first-place ranking in ease of opening an account and its top-tier performance in ease of exploring online banking and customer support, Keynote said.

A separate study, the Keynote Service Level Rankings for Banking Web Sites, looked at the technical performance of banking sites, including overall site responsiveness and reliability. National City, Citibank and Wells Fargo topped the list in terms of reliability, meaning those sites were highly available and experienced little or no downtime, Keynote said. Wachovia, Chase and National City were tops in terms of site responsiveness, an indication of how fast the sites displayed pages and executed transactions, Keynote said.

"In general, the banking industry is experiencing minor reliability issues, with only 3 of the 10 banking sites studied showing better than 99 percent availability during the peak periods, a threshold reliability rate recommended by Keynote for most industries," the study said. "Two major banking sites experienced more than 18 hours of outage time during the four-week evaluation period. Several leading bank sites also demonstrated major load handling issues, indicating that their sites cannot support the current load without significant slowdowns in performance."

The final study, the Keynote WebExcellence Scorecard, ranked 29 banking sites for online excellence according to their use and execution of more than 290 industry best practices. The sites are ranked for overall excellence and in four online categories, including online banking functionality, ease of use, privacy and security and quality and availability.