If the file you are loading isn't really big then you can use File.ReadAllLines:
List<string> list = File.ReadAllLines("file.csv").ToList();
As Servy pointed out in comment it would be better to use File.ReadLines method.
The ReadLines and ReadAllLines methods differ as follows: When you use ReadLines, you can start enumerating the collection of strings before the whole collection is returned; when you use ReadAllLines, you must wait for the whole array of strings be returned before you can access the array. Therefore, when you are working with very large files, ReadLines can be more efficient.
If you need a List<string>
then you can do:
List<string> list = File.ReadLines("file.csv").ToList();