Libraries for ADO.NET to rapidly bulk insert data into a database from a .csv file?

I'd like to know if you can recommend any advanced ADO.NET libraries for working with databases.

I've discovered that LINQ-to-Entities is great for pulling data out of databases, but not at all useful for inserting data into databases. Its missing functionality like fast bulk insert, culling of duplicates, and most of the advanced functionality you can achieve with pure SQL.

So: can you recommend some ADO.NET libraries that offer the sorts of advanced functionality that LINQ-to-Entities is missing?