would you advise is the best? The thing is I am on a limited budget of around £100-150. I want HD for my PS3 and I have looked around and monitors seem to be cheaper than most HDTV's. I am not really interested in TV as I watch most of my shows online. So, is a monitor quality worse than an HDTV's for PS3? What are the advantages and disadvantages of both. Any help would be appreciated.
Will an HD monitor look just as good as an HDTV or will it look worse?

The only disadvantage of a monitor is the obvious one. It doesn't have a tuner and you can't watch TV on it. So if you don't want to watch TV on it go with the cheaper monitor.
Also if you watch TV online , you can hook up your computer to your monitor and watch TV on your monitor.