The Home Depot has returned to the top as radio's number one advertiser airing 48,777 commercials for the week of March 30, according to Media Monitors. Walgreens moved up to #2 (from #4) with 43,807 ads aired. Last week's top advertiser, Geico, fell to #3 with 27,415 spots, followed by H&R Block (24,652) and McDonald's (23,808). The big mover was H&R Block, as we get into the heavy tax filing season. With just under 25,000 commercials, H&R Block took the 4th spot after not appearing at all one week earlier.