Answer by James Michael Hare for This code returns distinct values. However, what I want is to return a strongly typed collection as opposed to an anonymous type

For Distinct() (and many other LINQ features) to work, the class being compared (BarObject in your example) must implement implement Equals() and GetHashCode(), or alternatively provide a separate IEqualityComparer<T> as an argument to Distinct().

Many LINQ methods take advantage of GetHashCode() for performance because internally they will use things like a Set<T> to hold the unique items, which uses hashing for O(1) lookups. Also, GetHashCode() can quickly tell you if two objects may be equivalent and which ones are definitely not - as long as GetHashCode() is properly implemented of course.

So you should make all your classes you intend to compare in LINQ implement Equals() and GetHashCode() for completeness, or create a separate IEqualityComparer<T> implementation.