http://msdn.microsoft.com/en-us/library/ms175049.aspx lists the different types of indexes for SQL 2008 R2.
http://msdn.microsoft.com/en-us/library/ms175049.aspx(sql.100) provides the same list for SQL 2008 R1.
Unique is not a type of index - it is either a clustered or non-clustered index that has an additional property to prevent duplicate values.
Filtered is not a type of index - it is a non-clustered index on a subset of the data.
Included columns is not a type of index - it is a non-clustered index that has been extended to be able to hold non-key columns.
These three are all properties or attributes of other index types, and are not a separate index type.