I don't know them all, so feel free to volunteer which is your favorite! Why do you like them? Is it the customer service, the presentation, the power or craftsmanship? I've been sampling from each brand so far, so I'm not sure about mine.
Vixen Creations makes the wonderful VixSkin line of silicone dildos, which includes my favorite toy of all time: the Tex. So I'd have to give the prize to them.
I also like Tantus, Lelo, and Fun Factory. There's a few others that I've only sampled one or two toys from, but they're really great toys (in particular the MiMi from Je Joue and the Tango from We-Vibe).