Thought this may be a good sticky thread to the website based on experiences that I have had with companies and their products in the past. There's always a company that have more helpful than expected, gone past what you thought the warranty would cover and generally been a better product than the price suggests. I'm sure there has been others that have not gives a rats backside to your problems, they have just taken your money and run...
So to start it off with I'd like to thank two companies, Park tool and mountain biking batteries uk.
I'd bought part tools basic work stand a two years ago off of ebay (so not even through a shop), a brilliant basic work stand that is well built and a good investment for any home mechanic. Unfortunately I ended up damaging the height camp (my own fault for over tightening it) so could not change the setting. I ended up contacting Park tools HQ in US as I could not find a replacement part anywhere, a few days later on they responded to me by say they will be sending a new camp as a warranty replacement even without asking for proof of purchase.
http://www.mtbbatteries.co.uk/mountain-bike-lights/I've had two sets of lights from these (head and bar set up) and they work really well considering the price, I've had them for two years with out a single problem. After hitting a few too many low branches my head torch stopped working, again contacted the manufactures to see about buying just a new light (and not batteries to save money) but the response was to send it back so he could have a look. A week later it returned working again, all this for free.