If I were to gig and move my instrument around a lot, probably a good gig bag/soft case along the lines of Incase or Protec Contego. Specially if it's in a place where public transportation is the norm. If not, then a hard case.
The legendary Gibson Les Paul formerly owned by both Peter Green and the late Gary Moore had its headstock broken off in a road traffic whilst inside a hardshell case in the back of Moore's car.
That's a very sad story. Goes to show there is no absolute way to protect a guitar.... aside from putting it in a glass case and never touching it. At least a typical Gibson headstock injury can be easily fixed and usually makes the neck stronger than it was.
I like hard shell cases for the most part. Over christmas vacation I picked up a pretty cool nos Harmony polyfoam case for $20 that I kinda like, though it isn't anywhere near the protection you get with a hard shell case. SKB and TKL made really good hardshell cases. You will pay more for TKL since they are made in canada - they are excellent cases though.