It's become rare to see network affiliates air pre-90s sitcoms; for most stations, "Seinfeld" and "The Simpsons" is far as back as they go. What network affiliates (counting the CW, but no retro/subchannel nets) still air older shows?
M*A*S*H airs on a lot of stations.
Now, is it a drama, or is it a sitcom? I suppose there's a genuine debate on that.
KSTC Minneapolis (Independent) air Andy Griffith weekdays at noon & 12:30
It's only available on cable and Me TV (Unfortunately at a time when WBBJ in Jackson, TN doesn't carry it.) in my area. But on Charter's TV Guide it's listed as comedy/drama.