Brooks. My feet aren't the easiest customers to please and if my shoes aren't right, they're not afraid to let me know. Brooks provide luxury accommodation for my feet. I run in Brooks Trance and Brooks Adrenalines. In all races including Ironman distance I use S3 Racing Flats.
All these shoes offer really good support but one of the best things about them is they seem to last longer than previous runners I've had.