I need to transfer the content of a specific content type with bunch of textfield cck's to new D7 website, the thing is I found lots of ways to do such thing over the internet, I want to know what's the best and easiest and fastest way to do so.
I'm migrating from drupal 5 to 7.
Once I had a same problem and after couple of hours testing/working with couple of approaches I figured out that the best way to deal with this is using views bonus pack module to get a CSV export file:
This group of modules is sort of a recipe module that makes things easier by showing how to integrate some other modules as well as providing miscellaneous features that aren't distributed by Views itself. Sometimes these modules are only base recipes that will need to be themed and spiced up to fit your needs so be creative!
and import it via feeds module:
Import or aggregate data as nodes, users, taxonomy terms or simple database records.
You should use Migrate module.
The migrate module provides a flexible framework for migrating content into Drupal from other sources (e.g., when converting a web site from another CMS to Drupal). Out-of-the-box, support for creating core Drupal objects such as nodes, users, files, terms, and comments are included - it can easily be extended for migrating other kinds of content. Content is imported and rolled back using a bundled web interface (Migrate UI module) or included Drush commands
check out the other modules as given in LINK
Backup and migrate
Table wizard + Migrate