I guess I built up some sort of tolerance for bad films watching Movie Macabre in the 80's, as I find some of the KTMA era MST3K pretty darn funny. And it's worth seeing the show evolve into the MST we know and love at least once.
They riffed on a Space:1999 tv-movie, and some really cheesy sub-Irwin Allen disaster movies back then. I wish that they had been able to redo those movies on Comedy Central, as they did with Gamera and other Sandy Frank dubbed Japanese horrors.