The book Essential LINQ provides a great one paragraph summary of the benefit of LINQ:
LINQ does more than simply add new
features to the language. It
introduces a delcarative style of
programming into the C# language. The
declarative programming model allows
developers to craft code that
succictly captures their intent,
without forcing them to worry about
the order in which events take place,
or their precise implementation. It
allows developers to state what they
want to do, rather than how it will be
done.
