The trick to build a cleric that dominates is simple -- stop caring so much about your friends. When your party members are pleading for healing in round 4 of the fight, the CoDzilla's time is likely better spent wading into the fight solo, as they are fully buffed and can likely handle the encounter all by themselves! With a party that takes care of their own in-combat healing (potions/Healing Belts/lay on hands/scrolls), the cleric becomes infinitely more powerful. In addition, using a wand of cure light wounds or lesser vigor out of combat to preserve spell slots also helps a cleric extend their staying power. 750 GP split among 4 PCs is easily affordable by level 2, but many groups simply expect their cleric to patch them up, for free, all day long, and then complain when the cleric is nothing but a heal-bot!
Wise clerics rely on only one or two critical in-combat buffs to reduce buffing time, with other buffs being added via long duration spells, persistent spell (with splatbooks, of course -- preferable with Divine Metamagic), or quicken spell (again, preferably with DMM). If given extra time to buff, of course, a cleric simply gains even more super-awesome power.
- In a core only setting, your low level cleric buff of choice on defense is Protection from Evil (+2 vs. everything on defense + handy immunities) combined with Divine Favor to help offense.
- Once you hit level 7, Divine Power is the buff of choice. Magic Vestment will be running all day.
- Once you hit level 9, Divine Power + Quickened Divine Favor and you're good to go. Greater Magic weapon and Greater Magic vestment run all day at this point. A Ring of Counterspelling with a Dispel Magic loaded into it can be easily had to prevent Dispel Magic from taking you down.
Limiting splatbooks pretty much just limits the number of encounters/day that the cleric can be fully buffed for. With DMM Persistent, the cleric will be running around with Divine Power all day for every encounter. Without it, he'll likely only have it for 2-3/day, although a wise cleric would try to get one copy on a scroll just in case a BBEG inconveniently shows up just before bed time.
A 9th level cleric with Divine Power + Divine Favor + Magic Vestment + Greater Magic Weapon running has stats similar to a fighter (14 STR + 6 STR = 20 STR; MV + GMW = level appropriate gear for free; D8 HD + 1 HP/level = D10 HD; Full BAB like a fighter; +3 to hit/damage takes care of misc. bonuses from feats like weapon spec). In addition, the cleric retains all of their spellcasting ability, making them powerful and versatile. The fighter can't change out feats from day to day, summon (or drive off) an undead horde, or perform recon with powerful divinations. Plus, the cleric comes with a strong will save, mitigating the fighter's biggest problem.
Extra goodies -- domains are hugely powerful. With the travel domain, clerics gain immunity to grapple from level 1 as well as access to great mage spells like Fly, Dimension Door, and Teleport. Luck lets you reroll 1x/day, also quite handy.
Melee clerics are the easiest to build -- their buffs play towards massive damage output + massive defensive protections. Archer clerics are viable in core only but become better when the Elf domain is allowed. Skill monkey clerics are viable with proper domain selection, especially if Cloistered Cleric from the UA/SRD is allowed. So, you can get quite a bit of variety very easily with your cleric, even in a core or mostly-core setting.