I bought the 2 of the shelf pictured below with the idea I was going to use them for my center channel, I was going to have one making an L and the other one mirror it, then have the center channel sit on top and between the two Ls. I thought it would look nice. Except I got one of the shelves today and the whole thing weighs 20lbs, my center channel weighs 25lbs alone. Is there ANY way for me to hang this on drywall? Does anybody have any experience using those 90lb drywall anchors? If I use the studs, then theres no way for me to center it above the tv. And even so, I would only be able to use one stud, since one shelf is 24" in length and the studs are 16" apart. I'm just afraid that if I dont do this right I'm going to come home to a smashed TV.

I have used screw anchors that have a pivoting bar to secure the anchor to the drywall with good success. http://www.itwbrands.com/product_details.aspx?id=4 and I've also used http://www.toggler.com/products_hwh_installation.html

use a long screw into a stud where you can and these heavy duty drywall anchors will take care of the rest

About how much weight have you been able to put on those successfully?

http://www.toggler.com/products_hwh_technical.html

I've used those quite a few times for various items and had at least 50 lbs on them..

I prefer to always hit studs but there obviously aren't always studs where you want to mount something. If you can hit 1 stud and use the rest togglers you'll be fine.

They main thing when hanging on just sheetrock is if all the weight is pulling straight down parallel to the wall not sticking out very far it can hold a couple hundred pounds before crumbling, as long as the anchors are not near an edge, tape, patch, or joint.

I would not hang anything on sheetrock alone that people will lean on, anything that extends out from the wall to provide leverage on the anchors, or anything that moves - like a tv on an articulating arm because it can eventually become loose or crack the sheetrock after lots of movement.