Best army in history?

The Roman legions (in general) at the height of the Roman empire, mid 2nd century BC or so when Rome had most of England, parts of North Africa, Gaul, Germania, Spain (back then) etc etc etc. SPQR!

You could also say Alexander the greats' army at the height of his conquest and sweeping of Saudia Arabia / Turkey / surrounding areas

Then again the best, most successful, largest and most feared single army in ancient history? Probably The Mongols, they had the largest single continuous empire (bigger than the British empire as it wasn't all connected) They invaded pretty much ALL of Russia, took ALL of China, India, modern day pakistan, Turkey and kept going west into Europe even, taking parts of Eastern Europe - historians say they could have taken all of Europe if they kept at that pace and just bulldozed everything the way

No army or country stopped them or beat them in a single battle during Ghenghis Khans' and his son (Ogedei Khan?) reigns respectively. (I may be wrong about that) but they were more or less undefeated

But just branding one specific army as 'the best' is a little... hard to say the least, so many factors contribute to a good army and we have no way of comparing the best against each other aside from just speculating to ourselves

spartans? didn't you see 300! True story, bro.

Mongolian or British? two biggest empires in the world. Imperiallists wouldn't get very far without an army.

It was only large once they'd managed to reform themselves after Stalingrad. Up until that point, they'd been beaten back and back relentlessly. Had the Germans defeated Britian, not had to worry about the Africa-Campaign, they'd have easily beaten the Russians into submission.

Largest? Yes. Most disciplined? Certainly not. The had no constraints on them whatsoever. Granted, Germany had done some pretty morally inconviviable things to them, but the Russians did worse on their return. The Commisars couldn't control them at all.
Nor did they have high-morale. Need only look at the number of men killed by their own Commisars and men due to retreating, for that.

Lastly, the T-34 could NOT take on a Tiger II with a high chance of winning. Firstly, there were only 25 Tiger IIs on the Eastern-Front. Belonging to the s.Hz.P.Abt 501.
The Tiger II's armour ranged up to 7" thick, and with the T-34 only armed with a 76.2mm weapon, it would have to fire point blank to even have a remote chance of penetration.
The T-34's armour, even with the revolutionary sloping-design, was still only 2-5" thick. The Tiger II was armed with an 88mm weapon; it would punch through it like wet paper.
Perhaps if the Tiger II had a damaged track unit, there were multiple T-34s and it was the only enemy around - then yes it might. Even then it'd be slight, the Tiger II had the new German turret-motor in it, and could turn 360 degrees in about 8-10 seconds. The T-34's could only turn in 15.

The T-34 was a terrific tank. And I've no qualms with the title "best tank in World War II" - But the German supiriorty in armour meant they took the prize there. Well, would depend what you catagorized them in; "Most kills", "Most numerous", etc etc.
It would, however, be the Tiger I that fought them more often. Even then, it would be a fairly one sided fight. Sloping armour was revolutionary, no doubt, but the fact the Tiger used the Flak-88 as its main-weapon just left the Russian tanks in pieces left, right and centre. Were the T-34 not a tank they could quickly mass-produce, it'd have been a loss on Russian Armour again, and again.

At the moment its got to be the british SAS

http://listverse.com/2010/01/11/top-10-badasses-of-the-worlds-special-forces/

Look who's at the bottom.

MI6 isn't special forces. And that article is written in the style of a typical internet warrior who gets his information from the interwebs

The Irish Army, like, duhh. Keeping the peace for several decades in various unsettled places.

Otherwise, any army that prides itself on military excellence and training and really thrives off it- Spartans are one obviously, The Red Army another and possibly the German army of WWII as well.

still... the sas bit is true

The Red Army another and possibly the German army of WWII as well.