I stick with singular for table names and any programming entity.
The reason? The fact that there are irregular plurals in English like mouse ⇒ mice and sheep ⇒ sheep. Then, if I need a collection, i just use mouses or sheeps, and move on.
It really helps the plurality stand out, and I can easily and programatically determine what the collection of things would look like.
So, my rule is: everything is singular, every collection of things is singular with an s appended. Helps with ORMs too.
