I too have one of these.... I stopped conning, bribing and leaving things around the house when he was 6. It was way too hit and miss. At 8, it is about choices. I tell him "you will play a sport" and give him the available choices. Ten I give him a couple of days to decide. If he hasn't I give him a few more days. If he still hasn't made a choice, then I do. This method works for anything, books you want him to read or chores that need to be done. My kiddo seems to need to feel that he has some sort of control and by allowing him to choose, things have gotten much better.
The secret to success here is that I, the MOM, am equally inflexible and have way more patience!