I prefer combat, especially at the lowest levels, to be very dangerous. Dangerous combat is motivation to find creative solutions to obstacles or plan violent action with a bit of common sense that hints at a desire for self preservation.
Can I ask you the same question then? How do you define "very dangerous"? How often do 1-3rd (low level I think) PC's die in your campaigns?
See, I look at the math and it shows a somewhat different picture.
Take a Basic D&D fighter. He's got 5 hp on average. So, any given hit with a weapon has a 1 in 3 chance of killing this character. That's pretty high. However, that's not the whole story. A 1st level Basic fighter will likely have plate mail and shield (easily affordable at 1st level in Basic) so an AC of 2. The baddies, by and large, have a THAC0 (yes, I realize Basic didn't use THAC0, but, the principle is the same) of 19 and very little way to gain attack bonuses. So, generally speaking, they're only hitting about 15% of the time. A 1 in 8 (ish) chance of hitting and a 1 in 3 of killing means that you've got about a 1 in 20 chance of dying in any given round. Not particularly high.
AD&D is largely the same. The fighter will probably have an AC of 3 (banded and shield is easily affordable) and given a somewhat more generous chargen method (4d6 arrange to taste vs 3d6 in order) he's likely better than 5 HP and/or 3 AC. The baddies deal about the same damage and hit about the same number of times. Again, about a 1 in 20 chance of dying.
3e changes things significantly. The fighter now has 12 HP (not unreasonable) but only about an 18 AC (Scale+Large Shield+2 for Dex) and the baddies now have about +3 on their attacks and can fairly easily gain additional bonuses - flanking, flat footed, etc. Plus, the baddies, instead of dealing 6 or 8 as maximum damage, now deal 12 or 13 points. So, they are hitting twice as often and dealing almost twice as much damage. Sure, the fighter has twice as many HP, but, he's taking four times as much damage. He's got about a 1 in 10 chance of dying.
Move over to 4e and the combat numbers don't significantly change from 3e. The attack bonuses and damage dealt are pretty close. But, the fighter now has twice as many HP as the 3e fighter. Plus, he's got healing surges which means he's likely going to access even more hp in a given combat. So, the chances are probably lowest of any edition. There's still a chance he's going to die, of course, but, it's probably around 1% rather than the 5 or 10% of previous editions.
Now, the question in my mind is, what's a reasonable chance? To me, 3e was just too damned lethal. It was ridiculously lethal if you played it straight and never fudged. There's a reason that Paizo AP's are considered meat grinders. They really are. To me, a 10% chance of dying in any given round is too high. That means that someone should be dying just about every combat.
And, if they aren't, I really have to wonder why?