How to recover data from Ext4 partitions?

view full story

http://askubuntu.com – I've removed an old HDD from a computer and to install in another computer to use for data storage (personal files, not system files) and the file system that I've used was the Ext4, then, for some reason I decided to install another operating system in this HDD, I used the same file system for this OS (Ext4). But then I realized that this HDD, had a lot of tv series episodes that I forgot to burn into DVDs. Now I'd like to recovery this old data. There is any software with GUI and if possible native, available to Ubuntu, to perform this task? Edit: Output of sudo fdisk -l: Disk /dev/sdb: (HowTos)