I also have to say that I'm not a very big Paladin fan.
Initially, I almost went with cleric because I'm not that interested in playing religious characters in general. Playing a religious character where 'faith' has been replaced with 'proof' seems even less interesting to me (ie, we know the gods exist), so D&D clerics are usually at the bottom of the list. I would, however, consider playing one in 4e if the setting I was playing in offered a more universal-style religion, similar to the "Temple of 10,000 Gods" or that one group that believed in the divine power inherent in all men (humanoids, really) and that is it was time to abandon the gods, both in the Kingdoms of Kalamar setting. Or in any setting where there was no proof of the existence of gods and clerics were running on blind faith. It wouldn't be my top choice because I'm averse to religious characters in general, but there are a few things I'd be willing to try if you either got rid of proof or had more universalist religious options.
And I've also created a 4e Holy Assassin character that was a Rogue/Cleric, with tactics inspired by the Assassin's Creed character and some D&D cleric abilities splashed in.
So I can't honestly say I'd never play a cleric. A paladin, however, is a pretty safe bet for a "hell freezes over" class for me, though. I haven't encountered a concept I'd want to play, personally, where I'd choose that class.