[troll]I found a helmet with 3 more strength and 4 more armor in Diablo 3!!![/troll]
Honestly, it is hard to quantify best item. I've gotten a lot of weapon upgrades in Borderlands over the hundreds of hours I've played it...but is item strength a qualifier for "best"? Does getting a level 52 equivalent of a level 48 item make the level 52 version a better item? Does it add more to the game than the level 48 variant?
Then comes Binding of Isaac...so many items, with so many of them making drastic changes to the way your character plays. Some are situationally better rather than just having higher values than a lower ilvl. For example, recently I found a Number 1 on Cain. For those that don't know, Number 1 reduces your range to it's lower amount, as well as increasing your attack speed to the highest rate possible. Pretty awesome, right? Then, the next floor down, I found the Book of Belial, which, for those who don't know, greatly increases the damage of your shots for the current room when used. This made for a combination of pure destruction, killing bosses within seconds.
Other times, however, the Book of Belial is overkill, as your damage is already as high as it can go without the book, completely negating it's effect. This, to me, is a great item that vastly adds to the game...and Binding of Isaac is chock full of these kinds of items that stack in crazy ways. Giant shots that do max damage? Cool. FOUR giant shots that do max damage? Awesome. FOUR giant shots that have homing? Oh my, I'm in love.
The Borderlands equivalent of these items that are game changers are class mods. Granted, a lot of the class mods miss the mark of being significant, some, however, drastically change the way the game is played. Some so drastically change the dynamics of the game that you decide to change your build. However, these are, for the most part, easily obtainable and don't vary enough between each other to really warrant mention.
Diablo 2 had items that significantly change the dynamics of the game, however, they were rarely "drops". Most items with interesting effects were runewords. The obvious one is Enigma, which changed everything so drastically that it became a necessity for nearly all builds of serious players. However, a lot of them go under the radar and are unfairly criticized because of Enigma's prominence...such as Chaos which allowed Assassin's to base their build around Whirlwind, a Barbarian skill, and Beast which spawned the likes of the shapeshifting Sorceress.
MMOs, for the most part, don't have items that fit my bill of being considered good items. They do definitely have items that have a higher ilvl, and have marginally higher stats than items of lower ilvl, but I don't consider that a quality item...but I've ranted way too much.
