Waffen SS is very specific term you maybe mean SS in general? The Waffen SS was the "armed wing" of the SS. Most Waffen SS units were regular divisions taking part in combat, but the later divisions often were used for ocupational duties, normally ocupational duties were preserved for "less valuable" units. The best combat units would see front line duty. There are some exceptions to this which are mostly the phase of "rest and refit" Divisions which were in combat for a long time and/or had suffered heavy casualties were pulled out of line and filled with new personnel and got some "vacation". Despite being technically refitted those units then were involved in partisan combat and other occupational duties.

Some examples:

After the heavy fighting around Kharkov and later Kursk several of the "elite" SS Divisions were pulled out of the line to get refited or "upgraded". The 2nd SS Das Reich was send to France to get refited, the 1st SS Leibstandarte was send to Italy Rom ( it was planned to use the unit to as frontline unit against the Allied advance in Italy but that never happened ) . Both units conducted anti partisan operations.

The 17th SS Götz von Berlichingen was formed in France.

The 12th SS Hitlerjugend was formed in Belgium and trained there.

This also explains why the proportion of Waffen SS units was so high during the Normandy combat. The 2nd, 12th and 17th SS were some of the first units to reach the Allied Bridgehead. The 1st, 9th and 10th followed later. Of the 3 Tiger formations employed during Normandy 2 were SS.

The major reason to show SS units in film et cetera is because they sell better but some shows you likely think about got it right. Band of Brothers deals with a recon battalion of the 17th SS around Carentan which is historically correct. Its not really correct protrayed but the unit is correct. "Das Reich" was also fighting US troops after it arrived in Normandy.

The facination with Waffen SS units comes from the general idea that those units were "elite" and "special". So film makers will obviously prefer to display iconic Sig Runes.

Another Battle which was often protrayed and featured Waffen SS units was Operation Market Garden, again historically correct. Two battered SS divisions were refitting in the area and mobilized immediatly to combat the landings.