For the second time in as many months, a list compiled by AvianResearch reveals the BlackBerry Curve is the best-selling handset in retail stores, with Apple’s iPhone 3G again taking the runner-up spot. The sales numbers were collected for the month of December from the four major US wireless carriers, including AT&T, Verizon, Sprint and T-Mobile, which collectively account for 85 percent of all wireless subscribers.

Data is collected from 100 service representatives from each of the four carriers via AvianResearch’s Monthly Retail Store Survey. BlackBerry maker Research In Motion has topped the list since May with various Curve models. The touchscreen Storm is just below the iPhone on the December list at third place, with the Bold in the sixth spot, down from five in November.

Rounding off the top ten is the LG Voyager in fourth, LG Dare in fifth, Samsung Rant in seventh, which replaces the HTC Touch Pro, Samsung Behold in eighth, Samsung Instinct in ninth and LG Env2 in tenth. Online and business sales are not included in the list, so it is possible that other BlackBerries as well as Windows Mobile devices may affect the results.

The results nonetheless suggest sustained interest in both Apple and RIM despite the continued economic slump at the end of 2008, though the placing of three BlackBerries on the list potentially hands their Canadian creator a lead in overall shipments during the period.