Stella Show is an absolute must - so too is a meal or few drinks in Deniz Kapsi
I would definitely suggest a stroll into Old Village - I love the Robin Hood restaurant for a quiet meal with conversation and calm music in the background. Robin Hood is abut 5 mins walk from the Crossroads -you'll know you're at the crossroads when you see the lovely old green car (there's some photos on the site of it)
If you love swimming then a day boat trip - you get to stop at bays throughout the trip - and if you're brave enough can drive in off the boat. For a more relaxing boat ride - and a lovely calm day, try to Dalyan trip. The goes on the Dalyan river through the reeds (was in the film African Queen). You can have a mud bath too if you want. A real contrast to the busy swimming trip.
ICR have a new trip which has an overnight stay - that looks brilliant though I haven't tried it. The Day Trip, Riverside, Gokova, Cleopatra are all good value and great experiences. You'll find plenty of offers in bars and your
hotel for a Turkish night - make sure you choose a good one.
The food at the Prince Restaurant is to die for. Try the chicken cacciatore - absolute bliss. They have an excellent BBQ/ Turkish night on Thursdays.
If you haven't been to turkey before, you must try the dolmus - local minibus to get you around
icmeler and into marmaris. There's one that goes up into Old Village too. I usually get the water taxi at the end of the canal by the bridge over to
Marmaris and the dolmus back.
The market on Tuesday (or is it Wednesday?) is a must if like to shop or even just to experience it. Take comfortable shoes and plenty of water - it's covered but still gets very hot. There is a market in Marmaris too. If you like a more relaxing holiday I'd stick to Icmeler at night, Marmaris can get very busy and noisy - I hate crossing the roads there. It's also a very long road so you'd need to know where a restaurant was to get there.
Everyone I know who's had a turkish bath loves it - I can't (health reasons) so worth a try. You might also want to try a proper shave in one of the barbers.
I prefer quiet bars but you'll get loads of quiet and loud ones. Geordie bar is great - a bit of karaoke, game of pool if you fancy it or just a drink and a chat. Look out too for the Mitos apartments - their bar is so relaxing - this is on the canal. A stroll along the canal is great, there's bars/restaurants and shops and smaller seating areas where you can just sit and watch the world go by.
If you look on the ICR homepage you'll find all the excursions - some of them include a trip to a carpet or turkish delight factory - worth a look.