I actually think that nearly all of Heath's films are poor; mediocre at best. He is easily the best thing about Lords of Dogtown and Brothers Grimm (anybody else think that Terry Gilliam is over-rated?).
Few young actors get good material, and many actors never get good material. He was just hitting his stride....
Okay, my assessment:
Black Rock - adequate drama film. Nothing special but not poor.
Two Hands - good little film. It won awards here in Oz. Better than mediocre, even if I don't like Bryan Brown
The Patriot - can't say I like Mel Gibson either, and the gung-ho ending puts me off but standard film fare
10 Things - great teen flick. It's a good film for what it is
A Knight's Tale - as above. Pleasant entertainment. Better than mediocre
The Order - yeah, okay ...
Ned Kelly - good film although I quibble about the script in places
4 Feathers - I like it. I'd call it good
Monster's Ball - very good film although not one I'd willingly watch again, beyond the first half hour
Lords Of Dogtown - I love this film. I think it's an excellent film, Heath or no Heath
Brothers Grimm - I like Gilliam films and this one, while a mess, is charming
Casanova - good pleasant fare
BBM - it was okay
Candy - excellent little film
I'm Not There - totally loved it. Such a clever film
Even the very worst of his films aren't truly rotten. I wish he'd had the chance to show us more but it didn't happen. But what we've got left are a bunch of okay to brilliant films with no true stinkers, and Heath hangs on to his integrity in all of them.