HD TV lag

[Gamekid]

I was reading an article on a website that talked about lag with gaming when using a HD TV. I was wondering if this is true. It's like if you have an XBox 360, some games won't be playable on your widescreen TV. If you have a fighting game and you do something like a combo, there's like a half a second delay. I never heard of this. The only lag that I know of is when using a computer, if you start to type in Microsoft Word, then it can take half a second for your text to appear on screen as soon as you open word. Anyway going back to the HD TV lag issue, the article mentioned that certain models suffer worse then others. Has anyone had this problem?