Devs have scrapped a lot of them for the pretence of "realism" for the most part.
Myself, I don't see what's wrong with it, and one of the best implementations of health bars combined with screen flashes I've seen recently has been Alpha Protocol.
Firstly, you have your standard red, rectangular, red-cross health bar that is your base health. If someone gets this down, then you use a medkit, or it's gone until the next misssion.
Next, you have the Endurance meter. This is effectively your shield, and when you're being fired on, you lose health from that rather than normal health as standard from shields, as is the "take cover and wait for it to recharge" tactic if you're getting your ass kicked. A good, but not wholely original part of the Endurance meter, is that it varies depending on your gear and perks, meaning you can get over 350 endurance if you try.
Aside from your health bars, there's the common "OMGURGONADIEZ!" flashing red screen when you're on low health, and your controller vibrates to remind you of the fact, even if you have full endurance.
On top of all that, there's also the directional damage indicator, i.e. the red splodges that come up near the middle of the screen, pointing in the direction the hurty-ness is coming from.
While separated, the elements are all fairly pedestrian and dull, but they're put together so they all do their own thing, but they work well as a whole.