I've never had a dog that wasn't either a stray or from the pound. Therefore, coming up with a breed is somewhat difficult, and an educated guess at best.
When I was in high school/college, I had what the vet simply called a "Collie/Shepherd" mix. She was a stray that showed up at my aunt and uncle's place. We had just moved out to the country, so the timing was perfect.
Currently, I have a nearly 17 year old "Yorkie/Pom" mix. He came from the pound.