I think it gets more credit as a run then for actual storylines. I personally don't rate to many of the stories as classic if I did a top ten list it would look like this

1. Korvac
2. Vision
3. Under Seige
4. Kang (Busiek)
5. Red Zone
6. Avengers Dissasembled
7. The fall of Yellowjacket
8. Ultron Unlimitted
9. Vision Quest
10. Kree Skrull war