I strongly recommend Intesol Spain for TEFL training. I had an amazing experience - the course is demanding and challenging which ensures that you are well prepared to begin teaching as soon as you complete the program.
The trainers, Stephen and Kerry, are absolute experts in their delivery of the material, but more importantly, in just four weeks they are able to mold you into the teacher you hoped you would be. I greatly respect Stephen and Kerry; they are highly qualified for their positions and will give you the best training possible.
I really like that Intesol Spain is smaller than other TEFL companies in Barcelona because the trainers are able to provide a more personalized approach and take the time to meet one on one with the students and address all types of concerns - professional ones and personal ones too.
Practice teaching was a great experience as there are small group classes that you get to teach while Stephen or Kerry observes and steps in if necessary. Leading up to the class, Stephen and Kerry take you through every step of the planning to make the lesson as successful as possible. You are then provided with immediate feedback following the class and it is always constructive and useful, giving you a goal for the next time you teach.
I taught in the U.S. for more than ten years and definitely came into the experience thinking that I could just breeze through it - that wasn't the case. I say that so potential students are aware that you have to work really hard, but if you're willing to do so and want to learn from the best, then Intesol Spain is definitely the place for you.
And, as an added bonus, you have the awesome location of being two blocks from one of Gaudi's greatest works, the Sagrada Familia.