Are you aware those are propaganda videos? that the 'action and music' are made to make influenceable people like them?

They may be propaganda, but they are real videos. They even posted a video of a dead Russian soldier near Tadmur before Russia admitted he had died.

You say in a comment that they are the the 'underdogs and very brave' in another comment you say that maybe ' innocent people had to join ISIS to defend themselves from the sectarian Iraqi government' It sounds like you have already started being influenced by these videos and have adopted some kind of neutral stance about ISIS and some kind of respect for them.

Is that a bad thing? There are two sides to every story. I hear the western side every day on TV and the radio. I just understand their side as well.

Aside from that, it is very hard to argue that they are not the underdogs since they have both the worlds superpowers and Iran fighting them. It is also hard to deny that they are brave - cowards do not carry out suicide attacks.