Ironically, the only boss i cant solo in ZG (apart from Jindo for obvious reasons) is the bat boss :p
Using 53/13/5 spec and a bear pet (so dont even depend on thunderstomp at this point, next patch will give me Stomp + Swipe) and 2xt5 (more of a convenience i guess, but i would almost say mandatory to have 2xt5, not just for the healing itself, but for the mana you save on Mend Pet and as such less time in AotV and more dps, etc)
Snake boss: i wont waste too many words on this, just dispell the HoT, and move your pet out of the poison in p2
Mandokir: have your pet tank Mandokir at bottom of his stairs, yourself standing on the middle level of his temple (jump from the roof or stairs). This way the raptor will go into evade mode since you are healing your pet. Mandokir will never enrage cause you dont kill the pet; Mandokir will never charge you, since he is incapable of doing this, and as such he wont fear you or your pet at all. It all comes down to a simple tank and spank fight.
Tiger boss: dont worry about draining the healers mana or interupting the heals. Her heals are on a long cooldown, just outdamage it. Bring all 3 priests down to low hp, the healer last. Finish them off, p2 speaks for itself.
Spider boss: again nothing complicated here, there is quite a bit of damage on you though, i use Roar of Sacrifice on myself constantly here and bandage whenever she has just spit some poison on me and DoT has run out. She is one of the harder bosses for me coz of the moderate amount of damage, and the aggro reset when webbing pet. For that last reason i pretty much hug my pet.
Panther boss: by far the hardest boss for me to solo in ZG, but its possible. Bang the gong, nuke the crap out of boss before she despawns. Use Roar of Sacrifice whenever possible. Be very careful with when to use FD, and always use AotV just before you FD, you ll need the mana (volley costs alot :P ). Generally i FD right after she despawns, let bear finish off the remaining panthers (i guess gorilla would have easier job here :p ). Note: when you FD after she despawns, the panthers will still spawn, but will stay in their pens; when you stand up when boss appears again, ALL of them will come for you: use volley + explosive trap. I might have to change my tactics on this boss, i actually do already from time to time; it all comes down to improvising i guess. There are advantages to not using FD at all and just kill the panters, ill have to finetune this fight i guess. But for me it remains the hardest fight in there to solo.
Bat boss: at this point its impossible for me to solo (i know...). Reasons: damage output not high enough to counter the heals, even when specced for Aimed Shot. The only pet with an interupt atm has a 1 min cooldown on it, so not an option either (next patch gorilla might change that ofc). Only way for me to do her would be to spec for silencing shot i guess, but i cba with that. Besides she isnt really important for me.
Fish boss (Gazh ranka whats his name): tank and spank fight, occasionally resets threat, just be ready for that and you ll kill it. I reckon the turtle poly book he drops will sell for quite a bit, but meh ill have to wait and see :p
Hakkar: with only one aspect alive in my case, the bat boss, he becomes a trivial tank and spank fight. Pet is immune to his MC, and so are you since you are ranged ofc. With bat boss alive, all he does is an AoE silence (omg a silenced hunter, what can he possibly do!? ) and his shadowbolt thingy which hits for shite (use RoS on this). Easy fight.
Jindo: impossible, he WILL mind control you within 10 seconds, you cant control your pet at this point, so you basically have to watch you and boss ganking your pet while more and more totems spawn. Simply impossible to solo, at any lvl of gear, at any level, by any class.
AQ20 (same spec, same bear):
Kurinaxx: Fun fight, it comes down to a tank and spank with a few twists: you have to keep moving to avoid the sand traps, and stay away from pet (doh!) so he wont get the sand traps either (boss only casts it on you anyway). The stacking debuff on pet only becomes a problem when its -50% healing taken or worse. Solution: use distracting shot on boss, use RoS on yourself, wait for boss to put one stack of the debuff on you, then FD. Stacks on pet will reset and you can carry on. At 35% he will frenzy, but shouldnt be a problem, just continue what you were doing, taunting boss when stacks on pet become too high.
Rajaxx: 8 waves are relatively easy, boss (nearly) impossible. The explosion Rajaxx does deals damage equal to about 50% of your total hp, regardless of lvl. It can be resisted, but dont count on it. Perhaps its possible in NR gear, but havent bothered with that ><. It would probably mean you d have to the 8 waves in NR too coz i dont think you get ooc between waves and boss, but not sure, and FD wont work either i think, it being a bossfight.
Buru: only had one try on this, seems possible, but very hard to do. Eggs have 25k hp and you still need to destroy them to get Buru down. Your pet cant tank Buru due to a stacking debuff which does enormous damage. Again, only had one try on him, not gonna bother with him for now.
Moam: easy fight, his mana drain is a joke, but i keep viper sting on him to be sure (when he turns to stone he regens massive amounts of mana anyway, and i havent seen what an explosion does to me at this lvl, i dont intend to find out either :P ). Tank and spank, in p2 just kill the adds (which are immune to arcane shot btw, but np).
Ossirian: tried tanking him in Godmode, its *almost* possible. With next patch giving some more bonuses to healing (Mend pet glyph, more hp on pet, Silverback talent) it might be possible. I wouldnt recommend trying to kite him to crystals, it becomes to complicated to do it solo, as he still does knockbacks on you and pet, and he casts those vortexes that stun you.
Ayamiss: impossible, simply not possible without any form of self heal, and she ll sacrifice you; your pet is barely capable of killing the worm in time, but its possible. The damage she does on you will kill you though :P
Molten Core:
Lucifron and Magmadar are np, its the corehound packs around them that are a pain, havent found a way to solo those yet.
Only 2 bosses in there i can actually solo: Geddon and Shazzrah.
I pull them both in that corridor between Geddon's room and Garr's room.
Shazzrah: tank and spank, stand far away from boss. When he teleports just hold dps (aggro dump), let pet grab it, and continue dps. I also think if you stand far away enough (im Hawk Eye specced for Geddon, read below) he might not even teleport, but not sure about this yet.
Geddon: spec Hawk Eye, otherwise not possible. Do a pet pull, bring Geddon back and start tanking him. ALWAYS make sure pet is between you and boss, this can be a pain since pet has the tendency of trying to change his position, especially during Hellfires. I guess it aint the end of the world if your pet does get out of range for Mend Pet, but i didnt want to take any chances. I wouldnt recommend running in range to heal pet, even during Hellfire (as TheeRambo suggested 2 days ago); he can cast bomb on you too during Hellfire, probably the mana burn debuff as well. Essentially a tank and spank fight as well, just dont get the bomb or mana burn. Btw, on wowhead you can find the actual spells Geddon does, it has a 45 yrd range; but this is measured from the centre of his hitbox ofc, you are further than 45 yards away from his centre, even though you can shoot arrows from 41 yards to him.
On a final note: I soloed Geddon for the first time this week, binding dropped o_O. Got a druid in to duo rest of MC, Garr dropped his binding (WTF? O_o). Anyway, happy me, got all the mats TF in one day, bindings included ><. No Raptor mount yet though
Edit: forgot about Sulfuron somehow ><
He can be soloed too, you have no chance in hell of interupting the heals ofc, and you cant drag them away from each others, since its just....you :P
Solution: drain their mana, and keep dmg up, make them heal each other so they go oom (they actually wont be able to heal anymore at this point). Its an endurance fight basically, and one of those fights where 2xt5 is really mandatory. High dmg output --> more healing on pet + adds going oom faster