My mom is coming over tonight to watch a movie on my huge home theatre screen. I just recently upgraded to a high-def projector, and am using my PS3 to watch Blu-ray. It's freakin sweet.
And, Transformers is her favorite movie. Just happens to be the first high def movie I bought. :)
The difference is noticeable - enough to make it worth it. Especially for video games. I just rented Resistance 2, which is one of the highest rated video games ever created (one of only 4 games to ever receive a 10/10 rating on gamespot). I am PUMPED to play. Get ready for some serious digital carnage.