I have used a variety of sites for different things. I've got a long coated (and a short coated) lhasa so i need quite a few grooming bits and bobs as well as dog toys etc and I also buy stuff for my ratties online. I use various websites:
www.EquineCanineFeline.com - amazing value pet products and accessories, UK Based, unbeatable prices!
Everything for dogs: dog cages for dog crate training, dog runs and dog kennels, dog beds, dog leads and collar....... - www.canineconcepts.co.uk
www.petcetera.co.uk
Christie + Co - business agents, valuers, surveyors, consultants
to name but a few!

-- that's so weird. i typed the web site and now its a proper advert link.