I finally found what I was looking for !
Right, finding a website where you can watch videos without downloading them... Hummm, I was a bit sceptical at first, but after browsing into the site I became addict and a real fan.
No need to download weird software that nobody is able to understand the real function, or to have a certain granted access. In fact you registe and you can check if some of the most popular TV series are on the website such as Ugly Betty, Heroes or Dirt ( new series with Courtney Cox-Arquette)
The good points are: to watch the series in an unlimited time, as they are on the website ( a bit like YouTube but the full versions of the episodes), you can chat with the other fans, and the "spot" ( the internal fan site) are directly links to other people who are fans of the same series as you. The other good thing is the fact that they also gve you a list of the official websites for every series. But to make sure, it is not only based on TV series, but the website is conceived in a manner that if you are also fan of other theme like cinema or even actors, by only typing the name or the subject the website do a cross search and put you in contact with all the "spot" available.
The bad points, there are not many, to be honest, the website is quite young so a bit lack of videos, but I am sure with the popularity they will increase their video folios, thanks to the fans who upload their own. Another point is the fact that the downloading is really slow if you want to watch an episode at night, but quite quick during the day.
To finish, thanks to that website I can watch some of the series who are only broadcasted on an American channel like "dirt" and also another like " Heroes" which you can follow on Sci-Fi Uk.