Dungeons and Dragons is the Best at What it Does

   The Fun Lads Four and I are prepping for what we call "The Season" - in late Summer and early Autumn we tend to play a lot of RPGs. We're also talking about the various systems we're using: AD&D 1e and 2e; HERO; 5e; Pathfinder; the various D% system books from FFG's Warhammer 40K line; and we are all knee deep in WEG's D6 Star Wars.

The second weekend of August in 1990 a friend from a gaming group introduced me to a brilliant, beautiful woman. On our first "real" date we played WEG's Star Wars. Next weekend our sons are hosting a WEG Star Wars game to celebrate 30 years of being in love.

We started discussing how D6 is an excellent universal system and it has a cinematic feel, making it perfect for recreating movie worlds (which makes sense as the D6 system grew out of making the Ghostbusters and Star Wars RPGs) and that HERO, another cinematic universal system, is likewise really good at "imitating" a setting from fiction.
But discussed the limitations of GURPS, HERO, and D6 to do "generic" fantasy smoothly. As Nick said,
  "Sure, you can make a HERO Fantasy setting, but it can't be 'Europeland in general'; it has to be distinct and frankly a little gonzo to really feel right. I think D6 is like that but more."
  And from Jack,
  "And none of them dungeon crawl well. In the end the best system for a good dungeon crawl is still AD&D with a scant handful like Rolemaster, T&T, and, yes, even Palladium right on its heels."

  Which is why I am writing this - it was my turn to opine. Later I will discuss Rolemaster as an under appreciated universal system.

  HERO is one of my favorite systems of all time because with just a bit of thought you can do anything. Want to be Green Lantern? I know 3 approaches in HERO. Want to duplicate Traveller? HERO can easily do that, too. Want to make a Kojak/Beretta/Starsky & Hutch crossover? Sure! It is amazingly flexible.
GURPS is likewise supremely flexible (and let's face it, we all know GURPS is a HERO clone). D6 is likewise capable of doing about anything and has a few great ways of adapting dice pools to reflect scale (HERO 6e Damage Reduction rules are probably derived from D6's scaling rules).
  But these games share a problem that you also encounter in D&D 3/3.5/5e, Pathfinder, and some others and to a lesser degree in some others - "breaking the system".
What I mean by this take a little lead in, so bear with me. In these you have to make sure that people have reasonable limits on their dice pools/point allocations/feats that are essentially the GM not just laying down guidelines but also vetting every character and adjusting the villains and even campaign to match specific character builds. Here's an example from HERO -  a character I made called Basement Dweller/Shadowman. Without getting into the mechanics his powers allowed him to stay in bed at home while beating up someone on the other side of the world. All strictly RAW, all properly configured, not even a high points guy. But Shadowman forces the GM to specifically make villains, scenarios, etc. just to counter him.
In a oversimplified shorthand, IMO in a system where you need to seriously discuss, limit, inspect, and react to "character builds" a large amount of (for lack of a better term) gameplay occurs away from the table. And I am when I say 'gameplay' I don't mean getting supplies, talking to an innkeeper, etc., I mean 'deciding the outcome of traps and fights and such or forcing the GM to build them for you'.

And there is nothing wrong with this. After all, if I thought this was "bad" why the heck have I been playing HERO for 35 years, right?

  But I think AD&D is best at dungeon crawls because that isn't the case in that system. Here's the contrast:
  1) I have an underground adventure I made for HERO back in 1986 that I have used maybe 12 times. Every time I run it I must adjust it for the specific characters that have been built and brought.
  2) I have a similar thing in my AD&D 1e campaign that I also made in 1986 (same weekend, in fact). I have run it about 10 times and I never need change anything.

  Yes, personal anecdote, but I hope it conveys a bit more of what I mean. To sort of boil it down a bit, here is my core conceit:

To a very real extent AD&D is much more dependent upon what you do during play at the table vs what you do in character design and out-of-play metagaming. This leads to more emotional buy-in and tension during a dungeon crawl. Consequently, AD&D is "better" at dungeoncrawling than other systems.

This is one of the reasons I prefer to not abstract things like ammo, lighting, encumbrance,  and such any more than they already are - those 'precision counts' elements, IMO, add to the emotional buy-in at the table.
  Another illustration. When the Fun Lads Four did their very first dungeoncrawl as a team in years gone by (man kids grow up fast) they got lost underground. They had to keep careful track of every bit of food and water. They limited their use of light sources and carefully tracked every turn of light left. They were getting negatives for hunger and were worried the puddle they drank from got them sick and had only 20 minutes of candle left when they ambushed kobolds and got - a ham! Tension and anxiety followed by rejoicing!
To my mind that immersed them into the game much more than,
  "Roll to see if you have more illumination"
  "A 4; we do."
  "OK, roll to check for supplies"
  "A 13, but Betty has allocated an extra encumbrance zone, so with her +2 we make it."
  etc. ever could.

  In the end this is one of the main reasons I like AD&D so much and still play it.