Ted's Rent-It Center is conveniently located on Virginia Avenue in Hagerstown. They have a huge inventory of rental items. You can rent anything from party equipment like tables and tents to character costumes and metal detectors. The staff is very friendly both over the phone and in the store.
The prices are very fair and they always seem to have what I have needed when I needed it. I never even had to call too far in advance to reserve items.