My vote was for Eldar, but then I am biased as I was in the 101st Airborne so wide open hit and run kinda fits with my training. Sorta ends up coming out on the gaming table
No surprise the Orks come out on top. They have the most flexible orgainization, and the special rules make it so that even the newest player can get the most out of them in a battle. Put more bluntly, you can make a BIG mistake tactically with the Orks and they still have the potential to recover and win the battle.
Space Marines, Dark Eldar, Eldar, and Tau are more finess armies that require a more tactically minded player. Make a mistake with any of these armies and you are goin to have a real hard time recovering from the error. On the flip side of the coin these armies pay huge rewards to a player well versed in how to ue them, tactically.
IG, Chaos (Both), Siege, Necron, and Squats/Demiurg are more middle of the road armies. Not as flexible as the Orks, and not as restricted as the above Space Marines, Eldar, etc. in tactical flexibility. In other words, you will be restricted as to how the army is orgainized, but no to the degree of the above mentioned Space Marine, Eldar etc, but you will also be able to recover from a tactical error, just not to the degree the Orks can.
Overall, and it is the great strength of the Epic-A system, no single army dominates, and one would be hard pressed not to find an army that doesn't fit their style of play. Any Army, period.
With reasonable skill, and a bulldog determination to learn how to use your favorite army list, no single Epic-A army list to date cannot be used effectively on the gaming table. Using an army effectively doesn't always equate into victory all the time, but it DOES equate into always having a good game (win or lose) because you had a fun game. That, to me, IS the ultimate objective.
Jaldon