A csv reader class which reutrns CSV rows as List<List<string>>. So every row is a List<string>.

CsvReader.cs

public class CSVReader : IEnumerable<List<string>>
{
    private readonly string filePath;
    private List<string> lines;
    private List<List<string>> tokens;
    private List<string> headers;


    public string FilePath
    {
        get { return filePath; }
    }
    public IList<string> Header
    {
        get { return headers.AsReadOnly(); }
    }
    public IList<string> AllRows
    {
        get { return lines.AsReadOnly(); }
    }
    public IList<List<string>> DataRows
    {
        get { return tokens.AsReadOnly(); }
    }


    private CSVReader(string filePath)
    {
        this.filePath = filePath;
    }


    private void Read()
    {
        lines = File.ReadAllLines(filePath).ToList();
        headers = lines
                  .Take(1)
                  .Single()
                  .Split(new char[]{','}, StringSplitOptions.RemoveEmptyEntries)
                  .ToList();
        tokens = lines
                 .Select(l => l.Split(new char[] {','}, StringSplitOptions.RemoveEmptyEntries)
                               .ToList())
                 .ToList();
        
    }


    public IEnumerator GetEnumerator()
    {
        return tokens.GetEnumerator();
    }


    IEnumerator<List<string>> IEnumerable<string>.GetEnumerator()
    {
        return tokens.GetEnumerator();
    }


    public static class Builder
    {
        public static CSVReader CreateInstance(string filePath)
        {
            if(!File.Exists(filePath))
            {
                throw new ArgumentException();
            }
            CSVReader reader = new CSVReader(filePath);
            reader.Read();
            return reader;
        }
    }
}