Ok, let's narrow things down, Pally or Shammy?

So far I've only played a priest till 70, and I liked the healing, but not the DPS spec.
I am thinking about rolling a shaman or Pally so I can dps/heal, and with pally I can even try tanking maybe... I love the lore of both classes, being a knight of the holy light or a Master of the Elements (Green Jesus I <3 you) and I can't really make myself pick. I am, although, intimidated by the huge amount of paladins currently on the server, and that makes me scared to roll one, especially because I might not be as good.
What do you people think? Is there enough demand for shamans/paladins, what would be more fun in terms of healing? Or should I go Pally for the option to tank?

All the Pally specs are very good and fun in Wrath, but I feel like there are a ton of pallys already. Shamans are good too, although you wouldn't be able to try out tanking.

I've just got my shammy to 20 on Lordaeron, it's transformed my experience. So much fun!

Palas are good, especially retri, but there's a ton of 'em running around, and significantly fewer shams.