Atm in playing a condition necro with S/D + Staff and its simply insane. You won't kill as fast as some other classes, but you can basically grab any amount of mobs and kill them without going down.
In the Charr area there's some group event that includes a champion + 25 mobs following him. You can solo that shit on a necro. I did it at around level 50 so i wasnt even outgearing the content by much.
Any class can solo champions or vets with mobs, but Necro can take the most and is safest - especially since more conditions on you basically mean a bigger heal + like 3 ways to instantly remove conditions which is invaluable when taking several mobs together in Orr. Couple this with Death Shroud and an on-demand AoE Fear and you only go down when you screw up.
Agreed...I play a game with how many mobs can my Necro take down at once. AoE is insane with S/D + Staff