When I was a teen my parents went away on vacation and my mom left me a giant lasagna. I ate it twice a day every day for the whole week. I can eat lasagna every day without feeling sick, I can't do that with pizza.
I do love lasagna. I feel like I'm not well versed enough with legit Italian cuisine to really have an opinion but I'm sure there's something better out there.
There is no best Italian meal. It's the best food you can find in Italy. I've had lasagna in Rome that puts almost all Italian food to shame. And then the best steak I have ever had in Florence. Another way to look at it is every Italian dish is the best. :)
I do lean Cacio E Pepe. Get that done fresh with the wheel of cheese? Heaven.