My neighbor has a big TV but no surround sound system. Me I got a 25 inch. wega and a moderate 5.1 sound, I always invite him to watch movies in my house. One day I rented a good action movie and offer him if he wants to borrow it. Boy! You know what he told me, he said HE LIKES TO WATCH IT IN MY HOUSE.
until i got a FP i used a 27 inch tv for as long as i can remenber, and watching widescreen movies on it was just painful. The picture was like 8" high. The sound was great but the picture was so small you can't see whats going on. Its easier to shop around for video though because I think it's easier to tell diffrences in video compared to audio.
I do think it is easier to spot problems with visual sources, but what really causes me to place video second is the fact that the actual size of the image you're watching almost never matches reality (since when was Capt. Kirk's head two feet tall?) and especially: all available consumer equipment I know of can only generate a two dimensional image. IMO these two factors keep my brain from believing what it's seeing is actually real, no matter how awesome the image itself is.
But fess up: as mentioned already, how many people here (or their dogs ) have jumped out of their chair to answer the door......then halfway there realized the audio portion of their HT was simply reproducing the movie's doorbell sound?
So, I can tolerate small video imperfections but audio ones can really take away from the realism of a movie or TV show (though I can still enjoy a GOOD movie with crappy sound and picture if I have no choice).
BTW: I listened to movies for years with just a 2.0 system and didn't feel that deprived, because for me the rear/center/LFE channels are just icing on the TV and movie cake.