Ghostbusters.
When I call for them, I won't forget that I needed them.

ghost busters suck 
 
but the MIB really win they have better weapons and training

Now the ol Ghostbusters have never shot a live person with their rays, but I imagine that since crossing the streams creates a thermonuclear explosion, a single stream would fry you instantly. Im also pretty sure the MIB is lame. So the GBs take it. Actually, Louis solos.

bump

Ghostbusters win with prep. Egon is as smart as Reed Richards only with less of a budget.

MIB, better weapons, better training, and they have suits.

MIB.

MIB has access to all the confiscated technology of the universe and their surveillance network spans most of the globe, even though I grew up loving the Ghostbusters (and still do) I think MIB takes this. Although it would be interesting to see how a proton pack effects a live human being, depending on how destructive it is or what it does that could actually swing my vote. But I guess that information is something we don't have.

MIB stomps

Ghostbusters with ease.

MIB.

@YoungJustice said:

Ghostbusters with ease.

How?

All they have to do is cross the streams. BOOM!

The Men in Black. The have better resources, are trained fighters and battle physical beings more often than the Ghost Busters.