I watched Rosario to Vampire...it had no plot. Apparently the manga is decent but season of the anime literally had no relevant plot other than character introductions until the last 2 episodes. I gave it a 5 because it did have plot.

On the other hand I watched Maison Ikkoku which had a lot of plot. It dragged on a bit towards the middle but it was a pretty entertaining ride imo. Gave it a 9.