A whopping 89% of iPhone owners plan to stay loyal to Apple with their next smartphone purchase according to a recent survey conducted by investment bank UBS. A group of analysts from the firm recently commissioned a survey of 515 smartphone owners and determined that Apple’s iPhone is by far the most “sticky” device on the market. Apple’s next closest competitor was HTC, but only 39% of HTC smartphone owners said they intended to purchase another phone from the Taiwan-based vendor. RIM dropped to the No. 3 spot with a 33% retention rate, which was just half of the 66% it scored in a similar UBS survey from 18 months earlier; Apple had a 95% retention rate in UBS’s March 2010 survey, so it too declined over the past year and a half. Samsung (28%) and Motorola (25%) rounded out the top-5. A chart of UBS’s findings follows below.