I know you wouldn't normally rate your local vid. store but seriously, VideoEzy Kew stand out to me (from my experience of video stores). The staff are ALWAYS smiley and swift, and helpful. I've had a few free rentals by their proise if they don't have it, it's free, and when I've had a scratched or non-working vid. I've had it replaced or cleaned cheerily. They're really something else. They're my favourite.
Approximate cost: $3-15