For me, basically my "keeper rate" completely depends on what I'm shooting.
For my still life stuff, I'd say I get probably 1:3 keepers... though that's after spending anything up to a week or more building the set, selecting the props, faffing about and tweaking the lighting, and painstakingly arranging the composition using "liveview" in the camera, shooting tethered and a computer monitor echoing the liveview while I move around the props or lights to get exactly the right composition before I even THINK of pressing the button on the camera to release the shutter. Even then, I don't get it perfect every time, because I'm a bit of a beginner with studio flash and despite getting what I think is the right settings using my flashmeter, I sometimes mess up, and need to go up or down half a stop here or there.
For Landscapes, either on film or digital, i'm probably at the same level as
@Steve Smith - i.e. four shots from a session - be it on 6x12, 6x6x, 6x4.5, 35mm or digital and a 32gb card... For me it's not particularly that I am more considered shooting digital than film - I think it's just that I'm SO considered that I either lose the light, or I "burn out my attention span" after getting a few frames I'm happy with - OR, in some cases, I just see a few shots that I am happy with, and think "that's fine - I'm happy now, if I carry on and try and get anything else, I'll only get frustrated and irritated with myself."
For People Shooting - well - last couple of times I've been forced into shooting people, it's been weddings, and, on digital, I probably took around 1500 frames, culled down to 300, delivered 200-ish, and was truly happy with 1 or 2.
And for sports - well - Last couple of sporting events I've shot have been cycle races - I think I shot around 140 frames with 11 keepers on one race, and 400 frames with 25 keepers on the second...
But, ultimately, as
@KIPAX says - what goes in the bin doesn't really matter to anyone but you - its just a little more wear and tear on the shutter these days, and a little time wasted in culling the shots - its not as if you're shooting on film where every frame had a very definite cost.