IMHO - the Kodak P series, of course, I own one. Unfortunately, the have
been discontinued but may still be available via the Kodak online store.

BTW - asking what is the 'best' is really rather pointless. Everyone
figures the one they have is 'best' else they would have a better one.

I have the Z18 although I primarily use Nikon dSLRs.
It is a convenient way to have access to a super long zoom once in a while
and is a reasonably good, small snap shot camera.
If you use the Z18 in RAW formal it produces acceptable images at ISO 100,
maybe 200. The problem is just noise from the small sensor and it is very
ugly, by dSLR standards, at medium and high ISOs. In most images shot at
lower ISOs mediums can be reasonably corrected with a plug-in like
Noiseware, but only if you have all the raw bits to begin with. If you frame
the same subject with a dSLR at the same size, effective focal length etc it
is not hard to tell which image came from which camera. But you are
comparing lima beans with horeseradish.
If you use jpegs with any camera you get what you deserve. JPEGS are the
equivalent of having a drug store mini-lab run by an indifferent and poorly
trained adolescent inside your camera. Once in a while a good image might
emerge but most of the time it is a crap shoot.
I have looked at all the cameras you list or their immediate predecsessors
(which are largely the same innards in a different box) and in jpeg mode
there is not considerable difference between any of these cameras, unless
you are the kind of person who thinks there is a difference between a Polo
brand shirt bought at Costco and one bought at a Polo factory outlet store.

I think it's deliberate - it is EXACTLY the small
sensor that allows a (physically) small lens
to achieve those lovely zoom factors.

 BugBear

None of the above. Take a look at the Panasonic FZ50. Hands down it's the
class of all the bridge cams.