Using a brand known as Prior, from Norway, a barbecued turkey hot dog has a relatively high ORAC value (for a meat). This same brand was also tested in the frankfurter version, coming in with an ORAC that was about 20% lower. One may conclude that grilled versions are healthier, since they appear to contain more antioxidants, however it's important to note that grilling is also known to create more acylamide (a carcinogenic substance found primarily in the black grill marks). Perhaps the best solution would be to cut off the grill marks before eating.
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH Jan 2010