Achievements forum game

Nation Red - Atomic - 0.1%

Shogun 2 total war: Against all odds - 0.9%

DoW II Retribution - Overlord - 4.0%

Dungeons of Dredmor-You Have To Bang The Rocks Together, Guys 0,9%

Red Faction: Armageddon - Bug Hunt - 0.4%
Darksiders - BFA - 0.4% (glitched for some)

According to achievement stats, my rarest chieve is...

Gotham City Impostor: Chaperone Penetrator Pro - Kill 25 armored enemies using the Penetrator Ammo Mod for the Chaperone.

On steam, the % is 0.3.

Startup Millenium
Start Garry's Mod 1000 times
1.3%

Nation Red - Bucket Of Nails - 0.1%

Solar 2 - Hobo Star - 0.4%

That shit was quite HARD to get though. Amazing game.

Torchlight, The Horse Whisperer, 1.2%

Let's see...
Giana Sisters: Twisted Dreams - Harder than Quartz - 0.1%... actually that game has a lot of 0.1% achievements I have, meaning that not enough people play it for the % to go up. :/

Magicka: Breezed through 0.5%

Sherlock
Found all gold ammo, hidden throughout the stations.
0.5%

:D

Borderlands 2 - Challenge Accepted - 0.4%

The Binding of Isaac - Platinum God - 1.1%

Borderlands 2
Gadabout
Discovered all named locations in Oasis and the surrounding Pirate's Booty zones
1.2%

Realm of the Mad God(basically more than half are below 1% lol so these are 2 lowest):

Doer of Deeds .1%
More than 1000 quests completed with a single character

Orange Star .2%
Completed over 39 Class Quests

TF2(I feel bad, 500 hours in game, rarest achievement was a 2012 Halloween Event):

A Lovely Vacation Spot
Get to Skull Island and claim your reward!
2.8%

Torchlight:
Cash for Trash: 0.2%

torchlight 2: Trash Magnate - 0%
Sanctum: Like a Hawk - 0%
PVK 2: One Does Not Simply Walk Into Valhalla - 0%

i have some others