The iMacs have ATI Radeon HD graphics but they dont have a HD screen right, so if i buy an internal blueray/HDDVD drive it wouldnt play in HD.

no, the imac screens are very much hd. it would definitely play in hd if you were to get an hd disk drive.

If it's the 20 inch model, it has a 1680x1050 screen, and if its the 24 it has 1920x1200 screen.
HD resolutions are 1280x720 (for 720p) or 1920x1080 (for 1080p), so if you have a 24 incher you can watch either perfectly. ^_^

Great, thanks. Are TFT screens not named like tv screens then beacause yer it says 1680 by 1050 pixels but it only says HD on the graphics card.

Edit: Also if i download HD content form the internet can i be played back in quicktime or iTunes if in the right format. e.g can .mov be HD.

Like Zib says 1680x1050 is the dimensions of the 20" screen which is a little short of 'true' HD at 1920x1080. It will playback 1280x720 since it obviously has enough pixels to do so.
The graphics cards are called HD because they contain hardware to help with decoding certain kinds of HD video content. Appl doesn't leverage this particular feature in its drivers at the moment though. Technically, computers have been HD for years. I have had a smurf running 1920x1080 on a CRT using the stock graphics card. Display resolution took a step backward with LCDs, but the first HD apple (LCD) display was one of the ADC flat panels (I forget whether it was a 22" or a 23").

Quicktime will happily playback HD content, and therefore so will iTunes (though iTunes is restricted to mp4 and h264 files). Pretty sure Flip4Mac and the popular avi codecs support HD in QT too. VLC certainly plays HD avis.

So i would be better off just bying an HDTV then.

Thanks, Jake.

If you're paying the same money for it, I'd buy the Mac. Unless you really want a pixellated 60" monstrosity in your living room.

Yeah, I'd definitely get a mac, not an hdtv. Consider that the 24" imac has about the same amount of pixels as the hdtv does, but is 24" instead of 60". This means that the pixels are much more densely placed, resulting in a much, much, much sharper image than the 60" tv can offer. Just because they're both HD doesn't mean that they'll both have great quality.

Sorry, i ment get the iMac then at a later date gat a HDTV and blueray/HDDVD play.

LCDTVs still suck if they are much over 24". I remember someone boasting in our showroom that his £6000 plasma TV displayed 1380x800 or some such POS. I pointed out that for his money he could have bought a top of the line PowerMac G5 and two 30" displays. That shut him up.

Well im just gonna stick with the iMac i think.