Also, to get Roast Hog, at 9600ft, if you wait, you will see a meteor. Let it crash into Earth. Some people think you need Black Hole Son Achievement first.
In order of how good they are, the list goes as follows
Shift 3 (9/10)
Shift 2 (9/10)
Shift (8/10)
Shift 4 (8/10)
...but they're all brilliant!
Shift 4 is too hard...
 "SHIFT 3"){kind=icon}
 "SHIFT 2"){kind=icon}