I've just posted an article that presents both an FTP client class and an FTP user control.
They are simple and aren't very fast, but are very easy to use and all source code is included. Just drop the user control onto a form to allow users to navigate FTP directories from your application.
I like Alex FTPS Client which is written by a Microsoft MVP name Alex Pilotti. It's a C# library you can use in Console apps, Windows Forms, PowerShell, ASP.NET (in any .NET language). If you have a multithreaded app you will have to configure the library to run syncronously, but overall a good client that will most likely get you what you need.
For example (try doing this with the standard .net "library" - it will be a real pain) ->
Recursively retreving all files on the FTP server:
public IEnumerable<FtpFileInfo> GetFiles(string server, string user, string password)
{
var credentials = new NetworkCredential(user, password);
var baseUri = new Uri("ftp://" + server + "/");
var files = new List<FtpFileInfo>();
AddFilesFromSubdirectory(files, baseUri, credentials);
return files;
}
private void AddFilesFromSubdirectory(List<FtpFileInfo> files, Uri uri, NetworkCredential credentials)
{
var client = new FtpClient(credentials);
var lookedUpFiles = client.GetFiles(uri);
files.AddRange(lookedUpFiles);
foreach (var subDirectory in client.GetDirectories(uri))
{
AddFilesFromSubdirectory(files, subDirectory.Uri, credentials);
}
}