I feel like chiming in with the "I love Monoprice" as well.
I moved in June, and did a home theatre in my basement. Got a good porition of my cables, both in wall and out, speaker wire, face plates, etc from monoprice.
BUT...I also used summitsource (which I believe I found here when looking). They were better in price on some of the coaxial I needed, as well on some of the tools and faceplates.
For me, they were a good deal too because I live in Indiana and they are out of Indiana, I've always gotten my stuff in 2 days or less from them.
But yeah, I love me some monoprice!