I've used craigslist and eBay like most people, but have been pretty happy with the VarageSale app on my phone - a virtual garage sale. It seems to always have what I'm looking for, which is not always true of craigslist even though craigslist is more well-known.
One thing I like is being put into boards that serve only small areas. In the Denver area there are several and since I'm only in a few of them, I don't end up driving very far to find the items I'm needing. I also like that the app allows you to communicate with sellers/givers without having to take it to email.
Have you used VarageSale? Please let me know in the comments. I haven't yet used LetItGo, but I'm curious to know how the two apps differ. Thanks for reading!