The rundown as I see it:
3.5 is simulationist. It's a pretty solid game and a large chunk of modern RPG memes are based on it; DM of the Rings was written as though the players were playing it. The primary issue is huge power disparity in classes; if your wizard or cleric doesn't deliberately hold back their full potential, your fighters and rogues and stuff are going to feel pretty insignificant. Also, there's a fair amount of rules clutter; moving silently and hiding are separate skills, for example. There's also an alarming amount of splatbooks, and practically anybody who's trying to optimize will take a couple of prestige classes at minimum.
4e is World of Warcraft. The game is meant to be run as that sort of hack-and-slash sort of campaign Gygax hated; almost none of the "powers" characters have are described to have any usage outside of combat and the game expects players to quickly load up on magic items for no reason. Also, there's a lot of really stupidly-written rules, like, Iron Heart Surge* level stuff; Rogues have a power that lets them run past enemies to make them attack themselves, and Vampires are a class. It's not impossible to have fun here, but the game doesn't really lend itself to the kind of character- or plot- focused gameplay that D&D pioneered in the first place.
Pathfinder is sort of a medium between the two; it's basically a heavily modified 3.5 with rule edits to make it more balanced and streamlined. It nerfs formerly powerful classes a little to make them less lethal to game balance, and buffs most of the physical classes, along with introducing classes that blur the line between magical character and physical character like Bloodrager and Investigator. It's also got a ridiculous amount of free, legally available content on the Internet; whereas D&D characters need at least four or five splatbooks to make the kind of character optimization guides recommend, I've never found content in a Pathfinder guide not described on the SRD.
* Iron Heart Surge was an ability for a certain 3.5 class whose wording implies you can use it to stare into the sun and not go blind, or dive into the ocean without holding your breath and not drown.