Well, for me - WGC has been awesome. I've placed about eight different orders through them without issue, and the longest I had to wait was a week and a half for the goods to get here. They seem to have a more diverse selection than a lot of other retailers.
Redwolf is a close second and I've placed about six different order with them. While navigating their site is just as finicky as WGC's - their prices do seem to be a little higher sometimes, but mostly they don't have the selection WGC does. That said, if I've come across an item that I'm looking for more details on, hands down Redwolf almost always has what I'm looking for in their item description.
Because I tend to place large orders (not just stuff for me, but for several others on my team as well) I'm always looking to save on shipping, so I try and consolidate an order to one vendor or the other instead getting hosed on shipping from multiple vendors.
I've used Hobby City before for batteries, and while I was impressed with the performance of the Zippy Pack LiPos they sent me, it took them a couple of months to make the things (they were out of stock when I ordered them, and back ordered). However, despite the wait the price and the shipping were reasonable.
I recently placed an order with RSOV, so we'll see how that goes...
As for gear, well our team has it easy that way using the old O.D. CF Combat Uniform and 82 Pattern Web-Gear. We have a couple of sources on Mod 1 and Mod 2 Jump Jackets, though we can still fabricate some of our own items (like helmet covers etc.) as we have the last Bolts of the original Canadian DPM Material.
Anyhow, this is an interesting thread and there are some retailers out there I'm not so hesitant to try now by virtue of some of the positive experiences you guys have detailed - Thanks!!