Manual blocking please.

Oblivion blocking: good.
Risen blocking: good.
Two Worlds blocking: not so good.
D2ED blocking: not so good.

Common denominator of good blocking systems in ARPGs: manual player control.

A pure RPG can easily get away with blocking done based wholly on stats and skills. It fits the conventions, the genre, the gameplay style. But 1st/3rd person ARPGs, where the player is given the responsibility of full real-time control over a character that spends much of the gameplay time engaging in player-controlled combat, work better by giving control of fundamental combat actions to the player (and supplementing outcomes with stats and skills). I stress fundamental combat actions, as it is of course possible to over-complicate control systems or make them focus on things that aren't fun to do. I wouldn't, for example, want to have to press B every time I want my character to breathe or H to make his heart beat. But I do, in an ARPG, expect to be able to influence whether I block an attack or not. If the game lets the player hit A to sidestep an enemy attack, or SPACE to jump over it, what's a shield doing in his hand if he can't press a button to raise it?