Why 2005? Though like hell I can remember every game I played within a 13 year period. That's close to half my life.
The first Prey or the Bioshock series comes to mind at any rate. Since in those games, you literally cannot die. So you can pretty much just be lazy and brute force your way through every challenge ever. Granted you can turn off the Vita chambers, though I don't remember if you could turn off the spirit world for the first Prey. I get the feeling though that without the respawns, the games would feel badly balanced and maybe even harsh in terms of health pickups and what have you.
Any JRPG I played within that period I would probably find easy. Honestly, JRPGS tend to be a battle of stats rather than strategy. can't beat something? Get more levels. Though I haven't touched a Final Fantasy since X, so I wonder if anything I played could be considered AAA. Xenoblade perhaps? Which I didn't find too difficult, though I don't think I considered it a massive walk in the park either.
Bethesda games tend not to be too challenging once you figure out the workings of the game and proceed to break the absolute hell out of it. But there was a time where I actually found Skyrim difficult. Giants were one thing, but the Falmer were some absolute brutal shit before I was completely decked out in Daedric/Dragonbone. They tore through my Ebony like genestealers through terminators. But well, once all is said and done you become a literal unkillable god. You can turn up the difficulty but it just turns everything into absolute damage sponges which is just no fun.
But I think it just tends to be that way for RPGs. They are difficult until you figure out how to abuse the shit out of the game. Wasteland 2 was whipping me, but then I figured out ARs were absolutely OP and I just wrecked everything. Pillars of Eternity was kicking the shit out of me, then I figured out knocking everything on their arse with Ciphers got you through most fights unscathed. Also lol paralysis scrolls. Though those aren't exactly AAA games.