Get your tank(s) defense capped, and you can pull of OS10 (zero drakes), once you get used to the movement.
You can probably do a couple of bosses in Naxx10 with crap gear, as long as you pull off the strategy correctly. I would say the first boss in the first three wings (not patchwerk), and perhaps a few more deeper in.
I would do Naxx10 in this order (skip to the next wing as soon as you hit a wall)
Anub'rekan is easy.
Ferlina is not bad, once you understand the gimmick.
...And the last boss in Spider wing.. Mexxa or whatever, she'll beat the crap outa you until you've got the gear.
Noth is easy.
Heigan can be solo'd, provided you can stay alive that long. learn2dance
Lotheb is easy, but still a gear check (can you survive long enough)
Razuvious is more of a "is the encounter going to glitch out or not" check.
Gothic is easy, just work together.COMMUNICATE!
Four Horsemen can be done by 2x boxers, but its a survival gear check.
Patchwerk is a hard gear check. (actually the entire construct wing sucks)
Grobbulus sucks ass, due to excessive movement.
Gluth is going to stop you dead until you out gear it, or learn2kite really really well
Thaddius isn't bad, but is a pure DPS gear check (if you can get here, you can kill him)
But there is still a lot of bosses YOU CAN do, provided you can survive the learning curve. Anyone who tells you different is just a gearscore troll.
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