HighDEF TVs ? Need Info

[RubberDuckie]

My 27" TV finally died and I need to replace it.
I am looking at something WideScreen and HighDEF.
I have a question and will take any other information:
I have a comptuer hooked up to this TV (the one that died) and with a regular TV it could do 640 (and the new card will do 8x6).
Will the addition of HighDef allow me to use Higher resolutions? do I need anything specific? Is HighDef really worth it?

All I really use the TV for is DVDs and my daugher watches Disney.....So will I get a benifit from HighDEF with DVD and Computer use?

Any TV suggestions....?

Thanks for any infromation...