Looks like Verizon Wireless has a fresh supply of ammunition for its next wave of commercials for the Motorola Droid.

In the latest annual survey by Consumer Reports, released Tuesday, Verizon topped the rankings of major wireless phone carriers in the United States. The survey awarded high marks to Verizon for customer support, voice connectivity and data services. T-Mobile came in second, Sprint third and AT&T came in last place.

The unscientific but widely followed survey, which spanned more than 50,000 Consumer Reports readers in 26 cities, found that AT&T’s main weak spot is voice connectivity, but the carrier got panned in everything except Web access and texting.

I’ve written extensively on the challenges that AT&T, which is the sole carrier of the Apple iPhone in the United States, has faced trying to meet the demands of data-guzzling smartphones on its networks. The popularity of the iPhone has been something of a mixed blessing for the telecom company. While the iPhone has clearly won new customers for AT&T, it has also prompted many complaints about dropped calls, spotty service, delayed text and voice messages and glacial download speeds.

“It’s been a challenging year for us,” said John Donovan, the chief technology officer of AT&T told me during an interview earlier this year. “Overnight, we’re seeing a radical shift in how people are using their phones. There’s just no parallel for the demand.”

AT&T has said that the company is spending a big chunk of cash on upgrading its network, including erecting an additional 2,100 cell towers to fill out patchy coverage and provide stronger cell signals. The upgrades are expected to be completed by next year, and the company has said it is already seeing improvements.

The Consumer Reports survey found that iPhone owners are willing to put up with a creaky network just to have the device: The survey found that 98 percent of iPhone owners liked their phones enough to buy it again, despite the sub-par ratings for AT&T.