I don't know anything about the counseling programs specifically, but the three universities are vastly different.
Gallaudet is a university designed for Deaf and hard of hearing students. Although the graduate programs do allow hearing students to enroll (only 5% of undergrads are allowed to be hearing, but there is no such quota for graduate students), you should seriously consider whether you would feel comfortable at a school where the vast majority of students are Deaf. I would imagine it could feel very isolating if you don't know any ASL - of course if you yourself are Deaf or at least know ASL, it could be a really great opportunity.
UDC is generally very poorly regarded. They have started building themselves up more recently and they are said to have some decent graduate programs (counseling might be one of them, I've never personally heard anything about their counseling program). However, previously they have been considered on par with community colleges and just tend to have a very poor reputation.
GW is a very well-regarded university and I have heard some very good things about their counseling program, but I am not familiar enough with it to give details myself.
I am assuming that you are not from the DC area since you asked about such different schools, but if you are really interested in living in the area, I would also recommend looking at universities outside the district in MD and VA.
