For powersports (ATVs, Motorcycles, Snowmobiles, etc.) "motorsportsdeals" is a good one. The eBay store link is
eBay Store - motorsportsdeals06: Snowmobile Body Parts, Apparel, Motorcycle Body Parts. They have tons of parts and accessories and a pretty good variety of vintage stuff.
I also recently bought a computer part from chattanooga_family_sales, store link is
eBay Store - Michael's and Becky's: Childrens Toys, Miscellaneous, Computers Laptops Parts. I was very pleased, great customer service.