3.5 really changed the equations on clerics. In 3.0, a non-casting focussed cleric could blow a lot of his/her spells on long duration buffs, do her thing in combat, and heal people with wands afterward. In 3.5, there aren't nearly so many long-duration buffs (and the ones that are there aren't as useful) so clerics who want to make use of their spellcasting capabilities will spend more time casting in combat.
That said, I've played or played with most types of clerics:
Archer clerics: I played one in Return to the Temple of Elemental Evil. She was incredibly effective as an offensive damage dealer for the party. However, as an archer, she generally tried to stay away from the front lines. This was sometimes problematic if all the chips went down and someone needed a healing spell. Fortunately, she wore light armor and, having buffed the party beforehand, didn't often need to do combat healing.
Melee clerics: I've played games with some of these guys around. They're handy to have in a fight but not as handy as a lot of people think they are. If they need several rounds to buff, the fight will often be over by the time they start going. If they use Quicken Spell to reduce that time, they're offensively effective, but tend to burn through their spells pretty quickly. Also, being tied down on the front line can keep such characters from getting to where their comrades need healing even more so than being an archer and staying away from the front line. For a party without a real front-line fighter, however, a melee cleric is a good substitute.
Spellcasting clerics: My main character's cohort in Living Arcanis is a spellcasting focussed cleric. She makes good use of the options she has to be effective but again, focussing on offensive spells can run her out of healing spells quite quickly. Fortunately, she can make scrolls to augment her prepared spells. The other weakness of such characters is that they work much better in larger groups 5-7 characters than smaller ones where everyone could end up on the front line at a moment's notice. (This is probably true of archer clerics as well).
Balanced clerics: My secondary Living Greyhawk character is a balanced cleric (slight melee focus but not too much). I think this is the best kind of cleric to be most party's only cleric--especially for small (4 or less characters) parties. The ability to step up and reinforce the front line when needed is very helpful. And not feeling obligated to charge into combat at the drop of an initiative die frees such characters up to support the party as needed. However, if there's more than one cleric in the party, I'd be tempted to go for a spellcasting cleric and a battle cleric or a melee cleric and an archer cleric instead of two balanced clerics. The strengths of the balanced clerics shine most when they're the only cleric in the party and need to fill multiple roles. Similarly weaknesses of specialty clerics are felt the least when there are multiple clerics in the party.
