Gormless Farangs (do not associate)
Touts and peddlers with baskets entering restaurants pushing wares (ignore)
Sketchy Taxi drivers (avoid as much as possible, get out the car)
Healthcare ripoffs (fortunately never had to deal with it)
Obstructed, uneven, unsafe sidewalks (Still fully ambulatory)
So actually nothing bothers me about Thailand really except transport ripoffs, lack of proper pavements. Plus something for the future that everyone has to deal with eventually.