Hiya debs
Well you've really opened a can of worms haven't you? I don't really think there's much between them. I could tell you what I use but it's purely a personal choice. You can choose from the makers whose names you know at a premium or buy cheaper ones from the makes you don't, but who possibly make the ones you DO know.
As a rule of thumb how about going mid-range or popping into PC World or something similar, always assuming you can find someone who hasn't just started that morning, and ask their opinion?