Easy topic. What are your top 5 rarest achievements?
Mine are: (Game - Achievement - What it required - % of other duders that also got it)
1) Marathon Durandal - Pfhor the Win - Beat the Game - 3.3%
2) RAGE - Obsessive Compulsive - Beat the game with 100% of items collected - 4.2%
3) Marathon Durandal - 11th Clan of the S'Pht - Completed The Citadel - 4.4%
4) RAGE - Gotta Have 'em All - Collect all playing cards in one playthrough - 5.3%
5) RAGE - RAGE Nightmare - Complete the game on hardest difficulty - 5.7%
Yeah, all of mine are from the same two games. Kind of annoying.
(If you go to your achievements and hover the mouse over "Sort by achievements", you can have it sort by rarity. To get percentage, just click on the achievement)
EDIT: Shit. It should be "What are your rarest achievements?"