To sum up:
You MAX
[W] damage, except any [W] damage that only occurs on a crit, like high crit.
any damage that says "add XdY damage to the attack" or "the attack deals XdY extra damage".
You don't max
[W] damage that occurs only on a crit.
any damage that says "once per day when you hit, deal XdY damage to the target" (like fiery weapon for instance).
Other damage that only applies on a crit (like the paragon feat that applies 1d10 damage on a crit).
Any ongoing dice of damage.
Any other form of damage that says "when you crit...".