I think I've gone on record enough by now, talking about how I grew up on 3rd edition D&D. I've never actually played much of it or Pathfinder 1E, but it's the ruleset I spent the most time with, and through which I discovered my fondness for the character building process. But I don't have any illusions that 3E wasn't an extremely lopsided system prone to bloat and breakage.
It was, or at least tried to be, granular and simulationist with certain facets of play, mostly combat. But it was pretty abstract and vague in a lot of other areas. Or, where hard numbers were given, it's apparent they weren't given the greatest scrutiny during playtesting- a few examples are economics, item weights, and the way the skill system tends to get out of hand and devolve into big dumb numbers (dumbers, if you will) at medium-to-high levels.
In my opinion the biggest gulf in direction, ambition, and quality exists in prestige classes published in core, splatbooks, and the Dragon or more rarely Dungeon magazines. They brought a flavor of player character jank to the biggest tabletop RPG on the market that hadn't really existed outside of the smaller d100 market before then, to my knowledge. Don't get me wrong, I know 2E AD&D kits could be wild sometimes. But you were typically limited to one at a time back then, whereas 3E players were mechanically incentivized to cherry-pick levels from a huge range of base and prestige classes to get the kind of character they wanted, as long as they met qualifications and the table allowed it.
This system and design philosophy allowed prestige classes to be hyper-focused in terms of flavor and abilities, to the point that many were considered really only for use by NPCs, which were built the exact same way as PCs. But PCs could still use them if they were on the table. There was nothing stopping them from tearing open those flavor packets and dumping some or all of their contents into the gooey mélange that was their character gumbo, except maybe the knowledge that it wasn't necessarily a good idea to do so.
All of this is rambling preamble to me exploring some of the quirkiest character options 3E had to offer, dealing mostly but not exclusively with PrCs published through splats and Drag Mag. I know for a fact that dozens, probably hundreds of other people have already written similar-but-better things across blogs and message boards over the past two decades, but it seems fun.
I don't mean to rag on any particular creation for its failings, except in instances where I very clearly am trying to trash something into oblivion. But otherwise, I love and celebrate this kinda junk. It was a weird, new time for writing player-facing material, and it wasn't an easy job.
I'll be pulling most of my information from the "complete" edit of the 3.5E SRD, or by digging into my old collections of books when the material hasn't been added yet. When possible I'll just link to the entry and make reference to it, and if you want to you can read along, to save space reposting entire tables or other minutia word-for-word.