Personally, I prefer buying from butchers, not least because most of the major retailers aren't much cheaper anyway for the decent cuts and they treat suppliers appallingly in some cases (which is what caused the horsemeat scandal IMO). I also feel the meat is a better quality in terms of taste, usually as it is hung to mature longer.
However, if you're buying from supermarkets then you can look for the Red Tractor logo - this logo guarantees the meat is raised to certain welfare and management standards. If the logo also has the union flag on it, it means it is British. There are other certification schemes for animal welfare - the RSPCA has Freedom Foods, for example.
Not all foreign reared meat has poor welfare - I've been to Argentina and seen beef reared in ethical systems, for example, but generally British standards are higher. There are also issues around things like clearing the rainforest in the Pantanal in Brazil to rear cattle on reclaimed pasture land - and all this means for the wildlife and ecosystem.
I don't believe organic is any better than free range in terms of welfare and taste. It comes down to personal choice - the only difference our cattle have from organic cattle is things like worming treatments, which personally I feel would be a welfare issue not to do. So I don't believe it is 'better cared' for per se than free range. Personally, I think battery produced eggs taste crap and I don't like the system, so we always buy free range. Organic is great, but if we organic globally, there would be a major food shortage problem - here on our farm, crop production would drop off significantly without fertiliser and pest control - and we have a mixed system of crops and livestock which supports things like soil fertility
I know a lot of people have concerns about meat at the moment, and my advice (and this is as a beef farmer) would be "eat less, eat better". I'd rather see people support butchers and farm shops (and the meat isn't always more expensive) and eat a bit less meat