Hello Adrian Hughes
I'll bet you a tenner as soon as your local Panasonic shop have HDMI equipped players they'll be telling you HDMI is the connection of choice
Keep in mind HDMI is a connectivity standard - it transports Digital RGB or Digital YUV 'Component' signals; done correctly RGB over HDMI will look less noisy than YUV over an Analogue (3RCA) connection.
There is no hard and fast rules here though - your TV manufacturer may have spent more time and cost on the HDMI Input circuitry (very likely as its the new big thing) and equally on a budget DVD player/recorder the Analogue YUV circuitry may be better than the HDMI Digital circuitry.
As russ.will suggests you may want to spread your net a little further than sticking with Panasonic and have a look for yourself at Digital vs. Analogue into your TV; keep in mind when you switch from Analogue 'Component' to Digital 'HDMI' you need to have a look at what 'setting' the TV is on otherwise one Input could be on Dynamic (horrid) and the other on Cinema (much more acceptable if its a Panasonic PlasmaTV).
Best regards
Joe