If the .Net BCL is drywall, Extension Methods are spackle

I know many people get upset at the very idea of Extension Methods, but I already consider them to be an indispensable part of my programming toolkit. I’m seeing so many times where a quick extension method can make code be much more readable. Other times an extension method against even a core BCL type seems to fill in a natural hole in the official API’s and knocks out a lot of duplication.