Worst edits/cuts to an MST3K film

Which movie screened on MST3K was hurt the most by edits for the show (or alternately, by them using a pre-cut version that damaged the original)? It's not that there are that many great movies on MST3K, but some like This Island Earth were definitely hurt. In some cases, cutting the movie down for time removed plot points, important scenes or generally made the film murkier than it otherwise would be.