I expect a driver to get me from A to B, and notice whether I'm interested in talking (in which case talk and be friendly) or not interested in talking (in which case don't talk please).
A half-pint of water is nice but hardly necessary - it won't convert a horrible ride into a great one, and its absence doesn't make a great ride a bad one.
So much is outside the control of the driver - a late night drive with no traffic is generally more pleasant than a sluggish rush-hour drive, but it's not the driver's fault.