HDTV picture quality question...

Here goes...my first post and it's not even audio related...you'll have to excuse me...cause I'm desperate.

I just purchased a Toshiba 34HDX32 and I've got a problem. Watching DVD's are good, I know it'll be better once I get all my cables...I've ordered them and they'll be here in a week. BUT, my main concern is the picture quality of regular TV. I used to have an older ('99) 27" Samsung and when watching TV, it looked not half bad. Now, on the Toshiba, the image is all pixelated, fuzzy, just generally unclear. Anyway, any ideas on how to improve the picture if at all possible?

Here's what I have:
Toshiba 34HDX82
Satellite (Starchoice, I'm here in Canada)
- Yes, it has S-video out but my bettercable Silver Serpent has yet to come...so that'll improve the image...right? In the meantime, I'm using a standard video cable.
- The majority of channels; ALL major stations (ABC, CBS, NBC, local, etc.) have this problem.
- The channels that do look GOOD, and yes, they look real good are the higher channels (Discovery, TLC, the Food network, etc.)
- The satellite receiver itself is hooked up via a standard/generic F-pin/CATV/Coax cable. I'm thinking of replacing this but have no idea what to get...I was looking at MIT but someone out bid me on those. Anyway, ANY help is much appreciated. Thanks for your time!