A variant Priest that used Channel Energy instead of spells, being able to channel energy to heal, erect a protective ward, bless items (such as an allies weapon, allowing him to smite with it), buff allies, etc. would be interesting. Instead of having spells, the Priest would have X number of channel energy uses a day, and start out with two or three different ways to use that energy (with using it to heal pretty much being a staple), depending on feat use. As he leveled up, he'd get more uses / day *and* he'd get bonus Feats that he could spend on channeling feats, each of which would teach him a new way to channel that divine power, to put up the magic circle of protection, or to exorcise an outsider, or to repel undead, or to smite the unrighteous, for instance.
No spells at all. Just channeling options and channel energy uses. One might put all of his Feats into smiting stuff and buffing stuff, and be more of a Fighting-Priest, while another might focus on more healing and protection effects, and be a support character, while a third might focus on channeling the energy into bolts of glowing energy and be a kind of 'blaster' priest who calls down the fury of his diety on foes at a range (instead of wading into melee like the Smiting-Cleric).