I carry a Gerber fast draw when I feel the need. Cheap (20ish bucks) and it has lasted me for 4 years with no issues. I don't want to carry an auto knife with the legal issues involved so a spring assist is great for me.
We are issued Benchmade Autos and some big honking Gerber Tactical knives where I work. The Benchmade is a great knife until you use the blade to pry into something and the Gerber works better for digging a trench than cutting anything (guilty on 1 count of each). We have got some newer knives in as well. We are issued a SOG Bowie that is laser engraved with our Headqarters' logo and have started seeing some Gerber spring loaded autos now too. Too many to keep up with. If I absolutely need to cut through something, I use a pair of medics shears and I always keep them on my kit (actually cut through pennies with them, because somebody said you could and I had to see it to believe it). All knives are great, but for their own applications.