Great coffee shop with delicious breakfast sandwiches, my (Jenn's) favorite is the chorizo goat cheese on the everything bagel.
If you're a big fan of kayaking you'll this is a great place to try out, but even if you're not there's a paved walking/biking trail from Siloam down to the park that a nice little walk (called the WOKA trail on all trails, if you want a map)
Nice place to take a walk, go fishing, biking, frisbee-golf course.
Has some good food and sometimes live music in the summer.
Cute antique store
It is about an hour away from Siloam Springs, but it is an amazing art museum surrounded by nature and outdoor trails, and it is free to visit their permanent gallery. Definitely worth the visit.
You really can't go wrong with Wright's! (Adam made me write it) But, really, it's an amazing Barbecue place, they have a few other locations as well, so you can see what works best for you.
A great little lake with mountain biking trails, a recreational swimming area, and picnic area.
Good quality ice cream, with ingredients sourced from the area, a delicious treat on a summer day.