Foy's is year-round. It's better to go now because it's packed at Halloween and it's more fun to browse at your leisure.
Young's is a good ice cream/petting zoo place. In the summer, they sell "trash can" ice cream, which is neon purple, smells like play-doh and is made of all the leftover scraps that go into the rest of the ice cream.
http://www.youngsdairy.com/
If you go straight south on 75 through Dayton, you will shortly come to Touchdown Jesus:
http://www.jeeeb.us/
Who is flanked on either side of the freeway by two truly magnificent flea markets, open year round but only on weekends.
There's a gigantic Hustler store at that same exit if you're into that.
Keep going south and you'll be in the general vicinity of the most fanfuckingtastic place in existence, Jungle Jim's.
http://www.junglejims.com/
maaaaaaaaaaaaybe 45 mins south of Dayton, but worth the side trip.