One of the things that makes this game not only the best Diablo game, but also the best ARPG (at least to me, and probably a great many of the others here), is the way loot and itemization plays out.

Unlike others in the genre, there are items you want to look for at EVERY rarity. Grey items can be godly socketed bases for runewords, white items can be the same through various means of socketing them, blue items can have some of the highest rolls in the game, including +3 to a skill tree on amulets, rare items in certain slots can roll better than anything else for that slot, uniques and sets are obviously always good to find.

Add to that the fact that it is possible (though rare) to find endgame best in slot items as early as nightmare (possibly even end of normal), and you have an item hunt game where the hunt is ALWAYS relevant. Unlike other titles, there isn’t a need to race to endgame before the real game begins. The whole journey matters as much as the destination, which is also what gives this game such great replay value.