Ohhh god, where to begin. The beaches are pretty rubbish if im honest, and not very clean. There are 3 beaches, the main beach, the top beach and the bottom beach. By the bottom beach (where you will find some pubs called linekers and the british bar) you can walk to the end of the beach and up and over the hill, just 5 mins away you will find a pretty quiet and clean little cove /bay of a beach , perfect and much nicer than the main beaches. Boat trips from the main beach are a good laugh, and the sea is perfect for swimming.
The saturday market is an experience to see tourist crap and also eat and buy local food, look out for the large flour pancakes they make with potato, spinach and local cheese...delish!
The temple of Apollo is nice to visit in the evenings as well (when its shut) because there is some nice little restaurants (one in particular) that you can eat in and overlook the beautifully flood lit ruins.
Hire a car and go and find the ruins of Priene, near the villiage of doganbey. They are MUCH more spectacular than the temple of Apollo, and in the middle of nowhere, located high on a hillside, its like stepping back to ancient times, you wont see a car or hear a sound, it is really well preserved and spectacular, YOU MUST VISIT IT, as not a lot of tourists will, and its a hidden gem (google it). While you have the car you may as well take it just the short journey from there to the national park where you can see all sorts of wildlife, you may be lucky enough to spot some wild big cats, wild bore (i saw one of them) snakes, all sorts of birds and amazing stuff. Take your cossies because its dotted with lovely little beaches, and you are likely to be the only non Turkish people there.... I like discovering things like that in a holiday. The drive from didum (altinkum) to priene is not far and on a near desolated road, so dont be put off.
you will be sold/ see all the other usual attractions, ephusus, pamukkale (dont bother with pamukkale its not what it used to be), the aqua park for kids is good. There is also another aqua park in Kusadasi which is close and also worth a visit. If you go on a Turkish night (which you got to do) and can see one advertised in the caravanseri in Kusadasi, then go to that one. You can also go swimming with dolphins in bodrum, which is meant to be good (not done it), those excursions are sold locally.
cant think what else, dont trust any 'helpful' Turkish person to do any deals / buy anything for you as a 'favour' they are taking a big cut of your money Nomatter HOW friendly they are.
thats all i can think of for now... if i think of anything else ill let you know (bet you wish you hadn't asked).