Payday: The Heist/YMMV

Crowning Music of Awesome: The soundtrack definitely makes you feel like you're part of an elaborate heist.
Goddamned Bats: The police are absolutely relentless.
Narm: Wolf. Just... Wolf. GIT DOWN MUH-FUGGAS!
That One Achievement: Noob Herder and Don't Lose Face:
- Noob Herder requires you to have three teammates with Noob Lube active and clear any heist on Overkill. While perks don't change ingame on levelups, you lose Noob Lube at level 5, pretty much requiring you to get it in one shot or else have everyone else drop out, reset their stats, and try again.
- Don't Lose Face requires you to have beaten every heist on Overkill with no hostage trading. See that block of text immediately below this? That is what has gotten in the way of 99% of the people gunning for this achievement.
- On a lesser level, I Pushed The Button And Lived can be irritatingly hard to get, due to the amount of sheer luck involved. The mission? Diamond Heist. The requirement? Enter the vault with the Overkill-only secret door still accessible, get the diamond from inside it, and escape with nobody in custody. Some people have gotten the Don't Lose Face challenge for this mission before this achievement.
That One Level: Green Bridge. How bad is it? Well...
- You have to use saws on four prison transports in an open environment, meaning you can easily get flanked, and you will. Repeatedly.
- You have to locate and escort ONE specific prisoner to a tower.
- You have to release one or two balloons so that a plane can pick up the prisoner. It is here that most people get fucked over ON NORMAL, the easiest difficulty allowed for the mission - there's a reason you want the plane to miss the first time.
- You then have to move to the boat on the bridge and then further down to the extraction point, IN THAT ORDER, after the prisoner is picked up, on a timer with an endless assault. If you stop for any considerable amount of time, you will not survive.
- The runner-up for this is Heat Street, which has the relatively minor problems of Matt (the guy you have to bring to a certain location) not wanting to go in the right direction half the time and the shootout at the very end.