For all the obvious propaganda on Al Jazeera, they've been surprisingly "fair" in their reporting, both in their choice of guest speakers (although they might cut some mid sentence), and in the footage they release, that for a keen observer sometimes contradicts the propaganda.
It's one of the best "complementary sources" of information about the conflict right now.
Compare it with RT, which is so state controlled, that it has to use exaggeration "ad absurdum" to convey even a hint of dissent (an interesting exercise for the observer to spot out, but quickly tiring).