Crikies!
There's so many to choose from.
Before I go on a rant and ramble; it should be noted that Warhammer does a FANTASTIC job of making sure there's no 'black and white'. Every 'good' army has it's resume of dark and disgusting deeds. Empire is full of infighting and corruption. Brettonians enforce a cruel and neglectful caste system on their peasants, forcing them into a Dickensian life so they can ride around living out their chivalrous dreams, Dwarves well...they pretty much have a clean slate.
Every one has inner demons...some fight to deny them.
My favorite, are those warped and twisted by their inner demons.
Antagonists make the lore.
In descending order:
1: Beastmen. The embodiment of savagery and mandkinds perversion by the runious powers (the ones that the Warhammer world revolve around...), the Beastial Warherds are the bane of civilization and want nothing more than to tear it down and see it lie in ruins. There's something primal that appeals to me in their models and their lore...which is relatively untouched. (hrmm.....). They don't rely on big warmachines, or overpriced monsters, but just teeming masses of hand to hand, hoof to horn monsters. Hacking and slashing they roll over their enemies.
This is the army that got me into WHFB. Come hell or high water, it's what will keep me there. May not be the most competitive, but I'll use every trick and instinct to rend their way to the top!
2. Warriors of Chaos: (for mostly lore). These are men from the roof of the world, who grew up knowing only battle and bloodshed. They are not born evil (mirroring some one elses opinion), but grew up only knowing what was around them. They knew the gods and life available to them. If they did not adapt to the harsh and unrelenting life of the north, they would perish. They are shunned as "evil" but truth be told, how are they that much different than the ambitious lords of the empire and their limitless avarice? Sigmar was adopted due to the lack of choices for most men...and some even see the fruits of the four gods of the north.
The concept of rugged and massive raiders is so similar to beastmen, yet a whole different lore...think of it to Apache raiders & vikings. (close as I could come using well known references). These are men who saw the true faces of the abyss and became the abyss. Donning the most vaunted of armor, they each strive to become the perfect embodiment of their gods. They live to spread their chosen god's word....through bloodshed, through pestilence, through magic and mutation, through sadistic glee...they are each a holy crusader. They each fight for their beliefs.
The most spectacular monsters are behind (or the forefront) of these unholy juggernauts. Dragon ogres who crush knights under foot and hack down phalanxes, trolls who spew death and ruin on infantry, hounds of vile hides and lighting fast speed, horses that know no fear or master....even Shaggoths that knew the world when it was young and with each strike threaten to brake the world's bones...
3: Dwarves. (for lore only) These tough and resilient fighters are the stoic and forgotten backbone of 'the good guys'. They have been wronged, they have been beaten, but they rise up again and again...each time with less and less... to face overwhelming odds. Somehow, they still find a love for mankind.
The lore of the glory filled halls and untold craftsmanship is beyond compelling. They are the only 'good guys' that don't seem to be standing on a soap-box preaching or that are overflowing with arrogance.
4: chaos Dwarves. What's better than dwarves? Independent arms dealers. These understated dwarves are the master smiths behind the "WMD's" of the world. They can harness demons and bend them to their will with steel, spite and the molten lava of their volcanic forges.
They were once dwarves, but like the norsmen, pushed to the edge of the void...and there they saw profit. Even the ruinous powers have changed them...the magic petrifies them with each use...but does that stop them? No. They embrace their self destruction in exchange for the power.
Plus, how can anyone deny a mixture of Babylonian/Assyrian & Russians? You can't. Just convert your dwarves, add some demon fuled mayhem and scores of slaves and conquer all.
5. Druchii. (lore and playstyle)
There's something amazing about the Dark Elves. yes you could say they are just generic 'elves gone bad', but in their seething hatred, there's a level of pompous grandeur that I can't help but love. Think Prussians mixed with the pretentious style of "barry Lydon" and add some twisted armor and slinky killing femme fattales! Their lore has so much potential, and amazingly written pieces. The Malus series was well done. Everyone plotting and scheming....just a grander stage for the orc infighting.
Most hated:
High Elves: In every fantasy Genre, the elves exist. I get that. They're a staple of the genre. In every genre, they play the role of the most gorgeous, the most gifted, the hight of martial prowess, the tragedy of the gorgeous elves.
I'm sick of it.
The mentality of "oh, we're the best. Why? Just because" is infuriating and just worn thin. I get it, you're gorgeous. I get it, you live longer. I get it, blah blah blah....to fight in our world you're descending from your high white horse (who also is better than us) so we should kiss your boots? No.
Elves are part of this world and in every genre they are aloof and act that they are distant and apart...yet realize "hey...we live here too!" just in time to be the deus ex machina and save the beleaguered men from the fate they were dying in by the droves to save the world from...and thanklessly.
Does the short lives of men make them less than the elves? No.
This pompous attitude and aloof xenophobic lifestyle makes them no less evil to me than the dark elves.
If you can do everything better than men, pay the price.
In my eye, the elven core should be double to triple the cost for what they pay. Why not? You're eternal, you don't have the numbers or breeding habits that the 'lesser races' have? So come out from the country club "ulthen" and fight like the rest of us.
They make me sick.