Ah, the bias against bards.
First off, the World's Biggest Dungeon line is stupid, right off the bat. If you're gonna say that, when the Bardic Lore check, as written in the SRD, says "Extremely obscure, known by very few, possibly forgotten by most who once knew it, possibly known only by those who don’t understand the significance of the knowledge" for the DC 30 check, that the dungeon is still outside the scope, you're essentially saying, "Hey, you, with the class ability! You can't use it! Hah!" It's not the bard's only class ability -- it's not like filling the dungeon with creatures utterly immune to arcane magic, for instance -- but it's possibly as bad as filling an entire dungeon without putting in anything that a cleric could turn, or any traps that a rogue or barbarian could get a Trap Sense bonus against. If you want to make it unlikely, slap that DC 30 on it. Don't just say no, unless you're also saying no to a bunch of other second-tier class abiltiies.
As far as bards go in D&D classes, I like 'em. They're probably my favorite class. If I'm playing, that's what I'd like to play. Of course, I have this strange and arcane concept known as "The ability to imagine flavor text that works within the campaign", and that apparently puts me in a massive minority.
Romantic hero campaign: The bard is a beautiful woman who sings songs of beauty and light while swinging her sword, and all her friends go "Dang, she's hot," and fight harder. Silly, yes, but the romantic hero campaign is an inherently silly campaign.
Gritty, music-not-appropriate campaign: The bard is a spymaster and teller of tales, and he can call out tactical advice gleaned from a hundred ancient battle sagas to help his comrades. It's completely the same, numberswise, but the flavor is different, and he tells legends in the same way. It's a Perform(Storytelling) check.
Oriental Adventures: The bard is a ninja, given his mix of mind-affecting (and illusion) magic and skill use. If pressed into a fight, he throws off his opponents (and thus gives his allies a chance to hit) by declaiming his deadly prowess as he fights -- the usual deadly ninja spiel. "I am the wind, the thunder that shakes the mountains, my blade shivers from the echoes of the death cries of a thousand demons, etc."
Humorous, anachronism-friendly campaign: The bard is The Mouth. He's Chris Tucker in Rush Hour. In fact, his bardic music is trash talk that pisses off everyone around him, rattling the nerves of his enemies and annoying his friends to the point where they get angrier and do a better job of hitting other people just to shut The Mouth up. "Oh, you think you gonna hit me with that Greatclub? Please, I hit yo' mama better than that last night with my OWN greatclub, and that was just 'cause she was askin' me to!"
On a mechanical basis, the bard is an excellent support character, and if you're comfortable playing a support character, he rocks. His buffs are good enough to take the pressure off the cleric or wizard to buff party members, meaning that the cleric or wizard can do other fun spells instead. He can fulfill the same secondary combat role as other lightly armored folks, helping to flank or providing the low-damage-but-important-to-hit attacks that keep enemy spellcasters busy. If there's already a party rogue, the bard can pick up the slack in any areas the rogue doesn't cover -- and he can be the face-man in a campaign that is more complex than simple dungeon-hacking.
The bard is lousy in a dungeon-hack campaign in which spellcasters have time to rest between each combat (thus making the "free up spell slots" thing a moot point), and in campaigns where the DM decided to give all the classes additional skill points or additional class skills, thus removing a lot of the bard's coolness (not to mention the rogue's...). The bard shines in any campaign allowing for a lot of NPC interaction and offering skill-based ways to solve problems beyond straight-up combat. While the players who like focus will lambast the bard for not being the best at anything on a level-to-level comparison, the bard is far and away the best utility player, and is almost never useless. He can contribute as a second-tier combatant, a secondary spellcaster for mind-affecting or illusion spells (and some buffs), a buffer, or a skill-user. No other class can do that. (The ranger comes close -- that class offers more combat ability at the cost of a little skill flexibility and a little more magical ability.)
But then, as I said, mystical ability to actually come up with my own flavor text appropriate to a campaign. I guess I'm just special.
