Just read the voltage coming out of the power supply dongle on the
LCD TV you're
considering and look for anything from 12-15VDC output from it.
The DC
regulators are inside the TVs so it doesn't matter if it's off a
few volts.

Bad advice concerning the consumer grade LCD TVs I know of.

The 120 volt AC to 12 volt wall wart *is* the voltage regulator, there
is no DC regulator inside the TV. I called technical support
concerning my Samsung SyncMaster 150mp and they said the voltage must
be a clean 12.3 volts plus or minus 5%. Clean means no high voltage
spikes or significant AC ripple. They said lots of folks are running
this particular monitor in emergency vehiclesetc., but only by using a
10-16v--12v regulated power supply (expensive), *not* connecting
directly to the vehicle's DC bus.

Typical boat voltages range from 10v or so when running heavy loads
like anchor windlasses, to 14.4v or so when charging. High voltages
will burn out the cold cathode fluorescent backlight circuitry, every
time. You either have an unusual LCD TV, never use the TV during the
top end of a 3-step charging cycle, or are just plain lucky.