About 5 years same as Susan.  They just kept looking and looking and when I finally told them their dog was no longer welcome in their seasonal rental they bought.

I would guess about 3 or 4 years. This owner had 10 properties for sale with 5 different associates. He would ask for my advice on each. When the time was right I told him let me show you how I sell Real Estate. Needless to say the first one sold relatively quickly and as the others expired they moved into the portfolio also. That was a lot of work but now we're good friends.

My few short sales took about a year from start to finish. There were no reason, banks just did not really move. Good thing, we had understanding buyers who waited patiently.

7 years.  They bought two homes.  I've since sold both of them for them.

I've had a couple that have taken two years to close. 

If sellers count, 7 years.

I met a lady at open house in 2006.  We kept in touch every so often.  I met with her and her husband in 2012, then listed and sold their house in 2013.

The longest it has taken me so far is 8 months to close. However, I have a few clients now that are working on a year+ and have not found their ideal home.