IList vs IEnumerable for Collections on Entities

Question

When I have entities in my domain with lists of things, should they be exposed as ILists or IEnumerables? E.g. Order has a bunch of OrderLines.

Answer 1

Most of the time I end up going with IList over IEnumerable because IEnumerable doesn't have the Count method and you can't access the collection through an index (although if you are using LINQ you can get around this with extension methods).