[quote=GreivousKhan]
With energy weapons. Skalla likes his lazers.And before anyone says otherwise, no the reapers are not shooting energy weapons. It's hyper melted slug, or magneto hydrodynamic, that launches molten metal at a fraction of the speed of light.
[/quote]

That seems rather redundant.

[quote=GreivousKhan]
Still more believable and cooler then lasers weapons.They also have a somewhere between 132 to 450 kilotons of TNT hitting power.
[/quote]

Laser weapons are legitimate weapons that, depending on what spectrum you're firing, can have truly devastating effects on organic and nonorganic matter alike. Gamma ray or x-ray lasers, for example, will deliver instantly-lethal doses of radiation into the confines of a ship should they strike the hull (which they will). 

Against them, armor won't save you.

Also, 132 to 450 kilotons is laughably weak for a race that's supposed to be beyond ancient and powerful. Modern earth would completely devastate the Reapers if their weaponry is that weak.