Eldar by far; they have some of the heaviest weapons and best monstrous constructs in the game.
Check out the chaos daemons codex.
AnswerImperial Guard Eldar and Tau Chaos, Necrons, Orks, Tyranids and Dark Eldar are considered the "bad guys".
Eldar Space Marines Imperial Guard Dark Eldar Tau Chaos Space Marines Witch Hunters Gray knights Chaos Daemons Necrons Orks Tyranids
Space marines Chaos space marines Necrons Orks Tau Space wolves Daemon hunters Chaos daemons Eldar Grey Knights Tyranids Blood Angles Dark Angles Dark Eldar
Dawn of War featured the Space Marine, Chaos Space Marine. Orks and Eldar Armies. Follow Up Expansions Featured the Imperial Gaurd, Tau, Necrons and Dark Eldar. Dawn of War II Features the Space Marines, Orks, Eldar and Tyrannid Armies
Many people would say Eldar, as dark Eldar have only had two codexes, so the Eldar have evolved more. Dark Eldars vehicles are not brilliant and when paired up with the Eldars fire prism, the raider and the ravager just cannot compete with the firepower. Eldar also have a different unit for every job, but unless you choose your army carefully, you will just end up losing most of the time. so Eldar is better for an older wargamer.It is indeterminate which army is better however it is my opinion that the Eldar are currently better because of the constant updates. The Dark Eldar have not been updated since second edition (we are currently in 5th edition) and therefore been left on the bottom of the improvement trend line. There is still something to be said about the speed and special abilities of the Dark Eldar and can still stand their own against every army.
You must have the previous games to play the other races. With the Original you get the Space Marines, Eldar, Chaos and the Orks. Winter Assault you get Imperial guard. With Soulstorm you get the Sisters of Battle and the Dark Eldar.
eldar
eldar
Eldar Ryazanov's birth name is Ryazanov, Eldar Alexandrovich.
Eldar Shengelaya's birth name is Eldar Nikolayevich Shengelaya.
Eldar Kuliyev's birth name is Kuliyev, Eldar Tofik.