League of Legends

[Kaden]

It takes 10 kill/assists to max out the item, so it's not like Mog's doesn't reach a fraction of its potential.

I actually didn't realize that was all it took to cap a Warmog's. That's actually not bad.

And yes, in terms of raw HP, Warmog's is the best item in the game. That said, HP is all it does. Sunfire and Randuin's are, I think, the best defensive items because, while they provide less raw HP, they give multiplicative defensive stats and provide other bonuses (attack speed debuff is particularly hard to come by, making Randuin's pretty badass).

The catch here, of course, is that Mundo is one of the few champs who really gets good use out of raw HP.

EDIT: A general point I like to remind people of as often as possible: until you hit ~160 armor/MR (not hard, really) you get survivability from armor/MR than you do HP. This is referred to as Effective Hit Points or EHP. So, the recommendation for going tanky is to grab a small HP item (Heart of Gold is an easy go-to) and then by defensive stats until you hit that threshold of armor/MR. Obviously, though, buying items with both armor/MR and HP provide the most benefit, since, as I said above, they're multiplicative.