Tbh, it depends on your dps, on my timeless geared prot pala I had problems getting past council in BT, and karathess in ssc.
Also king maulgar solo depends on the class and dps.
The rest is easy (i found sunwell to be very easy compared to the rest).
Everything is very easy once you get the general strat down. Only tricky boss is Lady V with her shield and everything....
Everything has been soloable for a while now.
Only difficult things would be the chess event and RoS, but that is due to the figth design, not due to underpowered gear.
Ecce homo ergo elk
Warrior: Second Wind, zzzzz. Only real hard fight is Brutallus (did it at 475ish as Protection, 500 is a joke for Arms/Fury but reforge for Expertise).
Paladin: Ret is probably the best for this especially with how easy it is to get 496+. Would only recommend Protection for Illidari Council if you have a crap weapon.
But yeah, most of the TBC stuff was soloable back in FL-DS gear in Cataclysm.
Edit: Does that one boss in SSC still nuke you for 50% max health if you have mana as your current resource? If so that's probably the hardest fight as a Paladin to do and Holy may be the way to go.
I don't believe that the first Sunwell boss, Kalecgos, is currently soloable. He portals you into the Demon's phase and without someone in Kalec's phase, the boss despawns rather quickly, forcing a reset.
"Fell deeds awake! Now for wrath; now for ruin, and the red dawn!"
they are most certainly all doable as Solo on a DK, the only place you may have trouble with is Sunwell, but thats purely because of mechanics (unless they changed the Kalec encounter)
Which was nice... I tried it in 5.0 and got rofl-stomped, then skipped him and went to Vashj.
Here is what you might consider an unexpected truth: The only place where I commonly see elitist assholes is here. I rarely encounter them in the game. The game as portrayed on forums is not the game that most people actually experience. - MoanaLisa
all of em are soloble, even ssc and bt
lady vashj can be annoying to find the corrupted dudes while being feared, they dont stay up forever so you have to be quick to kill em when you find em
also the room is huge so finding them before they die is hard solo, but it is doable!
first boss in bt might be hard aswell, i had a guildy come with me as i couldnt get the boss down fast enough on my dk (the gear is really bad xD
Every raid in WoW is soloable up until Cataclysm, with BiS gear.
Most of WotLK raids are soloable at lvl 90, never mind TBC. Kael'thas can be a pain in phase 3 though, when all the advisors are up; the mage can keep you permanently disoriented if you don't bring her down quickly.
In WotLK, Thorim in Ulduar is tricky because the encounter requires the raid to split up, some classes (and engineers) have found ways around this. And in ICC you'll need some help for the Gunship Battle. Valithria Dreamwalker is impossible for non-healing classes.
Easy if you have high DPS and a bunch of potions to bring along.
Yes. I did Gruul`s Lair, Karazhan and Black Temple last night on fury warr and blood DK.
Incredibly easy. Could pull the whole raid at once because the mob can not even hit you.
Even faster on fury warrior as Dragon Roar one shotted everything at once.
The council in Gruuls Lair took a few seconds longer because of the fears and stuns.
I did not expect it to be THAT easy.