too powerful:
Wizard, Warlock, Sorcerer, Bard, Druid, Cleric, Paladin
not too powerful:
Barbarian, Fighter, Rogue, Ranger, Monk
...
Now, there is another sense of "too powerful": "too powerful" in the sense that you cannot build interesting adventures for them. And the full casters gain increasing numbers of "campaign altering" abilities as they gain levels, which might not be your cup of tea. But the Paladin doesn't, so I'm still confused.
"Too Powerful" can be misleading. Too versatile, or simply imbalanced might be a more nuanced way of putting it.
Or, the 3.5 class Tiers put it succinctly.
But, let's just say...
Should be nerfed: Wizard, Druid, Cleric,
Could be nerfed a bit without undue hardship: Bard, Warlock, Paladin, Monk,
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Doesn't need a boost per se, but could be done better: Sorcerer, Ranger
Could use a boost outside it's best tricks: Barbarian, Fighter, Rogue
Needs all the help it can get: Champion, Berserker
Above the line shouldn't be getting any changes unless they rein 'em in somehow. Taking things away (like spontaneous casting from neo-Vanican), or adding back old limitations/restrictions or the like. Below the line could get some new options that improve the design, at least, but even then probably shouldn't increase raw power, at least, not at the things (or thing) it already does well.
So, yeah, a 'rising tide' or overall powercreep, not helpful.