Official "hardcore achievement runs" thread

Swear this thread exists already....

Anyways, I'm not an achievement hunter. The only achievement I have that could be considered hard to get is "Hexagon" from Super Hexagon. Sadly I don't have Platinum God yet on BoI, or else that'd be in the list.

EDIT: My hardest 100% run? I don't think I even own a game that does those. ._.

Hardest 100% for me? Hotline Miami

Beating Unholy Heights before expanding is tedious enough to be hardcore.

Well I did that in Skyrim before the DLC, although some mods screwed it up and I wasn't able to get all the achievements because steam.

red orchestra 2 achievments

Limbo. Had to try twice.
It took soo long. >_>
BOI was pretty easy to 100% though imo.

Portal, just because the challenges were tedious and the rest of my 100% games weren't that hard.

Just Cause 2: Get 50/75% in the Game. You have to play ages to get these. (Haven't got these).
Finishing the game on hardest difficulty can be tricky, but if you focus on improving only some weapons, it works.
Then there is an achievement where you have to kill 50 enemies, with inventory weapons, without losing any health. This is one of the Harder to get ones.

Not sure about the hardest, but I recently completed DmC. Hardly anyone beat Vergil's Downfall on Hell and Hell mode, probably because the that boss fight is unfairly broken, so it's probably the more difficult one out of that game. I didn't find Spec Ops too be so challenging myself, but FUBAR isn't available right away, so I didn't really bother getting achievements for it. Unless I'm planning to get all of them, I don't generally look to get them.

X3TC Dead is Dead run.

Fuck me that had some tense moments.

This is all I've got for 100%ing games.
So I'll go with Spec Ops as well -- even did FUBAR difficulty on the shoot-out epilogue for that. And while that game is challenging, I never found it unfair, which is probably a lot of why I kept at it. That and, like you mention, the fact that it doesn't have any multiplayer achievements -- I liked that too. Also wanted to do the coop levels, but my usual coop guy didn't ever have time for games anymore -- someday.

Runner-up would be HL2:EP2. "Neighborhood Watch" was the last achievement I needed, and that defeated me a number of times years ago. Tried it again later this year and got it in just a handful of tries. Or maybe runner-up goes to Limbo... can I have two runner-ups?

The List
Only some of them I would consider hard, those would probably be Dustforce, Offspring Fling, Payday and maybe Shadow Warrior

FUBAR wasn't really that hard. Yes, some chapters are annoying (especially 6th called "The Pit" and 13th - "Adams") but generally this game isn't ridiculously difficult.
For me one of the worst achievements was Big Tournament in Borderlands. You can do it easy if host is a some low-level player (enemies scale to him) but it still takes almost 9hrs to beat it (every arena is 2,5-3hrs long and you cannot pause it any way).
AVSEQ achievements also were pain in the ass. Some are broken (game resets their progress after closing and you have to do them during one session), the rest is hard because game is bad, really bad. "Audio-visual" puzzle game with annoying sounds and awful graphics covering the screen and disturbing in gameplay.
I don't like multiplayer related achievements too. I have few games (e.g. Binary Domain and Red Faction Armageddon) which are quite easy to 100% in single but their multiplayer component is dead.

Ed.
Oh, also Straight Flush from Poker Night At the Inventory. It's so random.