I remember when I decided to go from VHS to DVD and I have over 1,000 back then. To make it easier for me, we just moved the bookcases out onto the front porch and let them pick and choose. At night we'd just move them back inside until the next day. Because of the prices, I got rid of most all of the movies in 2 days time. I gave all my John Wayne movies to my boyfriend and sold all my 125 Disney movies to a co-worker as a set so that took care of a couple hundred of them. Now I've got over 2,000 DVD movies and yes, I've run out of room and in the process of having an entertainment center built around the flat screen TV in the living room.
When I first moved here, I had a garage sale and it must have been the wrong time of the season (May) as I couldn't move much of it. The catholic church had some new nuns moving into the old house next to their church and it was totally empty of the necessities so I met up with them and told them to come on over and pick out anything they could use for the house. The rest I stuffed in my mother's van and took up to a non-profit thrift shop in a little town 25 miles away.
Now I don't bother having garage sales but I still go to them. My sister and I both donate to our local non-profit thrift shop for the disabled where most of the employees are volunteers. Our rule is if we buy a top or pants, we have to give one or each back so the number of clothing stays the same in our closets. Also anything else that still has some worth to it, we give to them. Trash we put in the trash can, not to the thrift shop where some folks think they'll take anything.