Those tweaks old Chris mentioned actually wiped some of the best concepts of the movie, most notably the enemy alien (changed from a humanoid glowing gray to an eel...sigh) and the operation of the Stargate. (I don't know why they thought it necessary to add LED lights to the chevrons for the series. The gate looked much cooler as a big, enigmatic stone thingie.) The scope also got reduced (Abydos went from being on the other side of the known universe to another part of this galaxy.)
I'll agree partway with the Stargate operation, because I miss the chevrons opening but I like that they glow too. I totally disagree with the original Ra, because I liked how the show subverted the gray alien trope by making them good guys. If they'd kept the old Ra, we'd just see gray aliens being evil like they are in most media.