1.Entertaining

Simple reason it's so damn funny just see their act every damn day, from gin laziness and other character traits which makes it funny.also the gag that they made everyday.

2.not always gin-san
another interisting part of this anime is that the story doesn't revolve around gin-san an yorozuya, you may find someday watching stories aboout kondo-san.

3.expexted the unexpexted
here is another strong point of gintama series. you will never in a hot summer when your fan is broken , and you're trying to find replacement. you have to fight some terrorist that want to get some money making machine.