I have seen avenger series and they are just awesome.
But the avenders infinity war is a combunation of action and thriller . The story is of infinity stones which was taken by thanos. Avengers had to stop but they could not.
The movies series has collected over 5-6 billions all over the world. Marvel stories always stand out and are one of the best selling stories in the world.
If you have not watched it yet. U should go and watch it.
The performace of every character seems real as well as movies roles are unique and equally blended.