I had comcast standard extended basic cable till recently. No digital converter cable box. Just direct connection of coaxial cable to TV. Picture quality was good, not amazing or anything, but surely not bad either. Now i upgraded to HDTV. I still didnt get the Digital classic package though. HD channels are awesome. The other channels are really bad and snowy now. I read somewhere that the problem is with analog channels? What are these analog channels? Does switching to digital classic package make any difference?
Digital tvs must be fed a clean strong analog signal to perform in the analog domain. Otherwise, standard analog signals tend to display worse than on a corresponding analog set. Try titantv.com and antennaweb.org to determine what is available in each format.