We've been playing some Powered by the Apocalypse Games at the store. Those are light! Character creation is entirely self-contained — pick up a "playbook" (or class), and all the options are fully described right there on the character sheet. You could hand a group of new players a stack of playbooks, go grab a slice of pizza, and come back ready to play.
Playing D&D at the store, I've found that trying to walk new players through character creation is almost impossible. Too many options to choose from and explain. Maybe if we just stuck to the Basic Rules, but once you add the PHB classes and races in, it takes more than an hour to get through the "why does this matter" stage. Pretty much obligatory to use pre-gens. On the other hand, if you do use pre-gens, it's a pretty easy game to teach on the fly, and I find the rules derive very easily. I was able to absorb the rules of 5e and start DM'ing very quickly. (Though having played earlier versions obviously helps.)
I'm getting a Traveller game together for a group of new players who REALLY want to play a science fiction game. We're using MgT, because I have the hardback. I've spent a lot of time reading through the rules trying to get everything into my head. There are dozens of skills, many of which contain associated crunch. There are lots of little rules systems about law levels, operating spaceships, fiddly hand-to-hand combat, fiddly vehicle combat, fiddly space combat. I'm putting together a screen insert with rules and only have room for basic stuff. I imagine I'll need to replace it with "2nd level" material after the first session.
So, yeah, I'd put D&D in the middle. That being said, if Rules Light is a rating that says, "This is a game you can just pick up and play," I don't think D&D, even D&D 5e, quite gets there, so I voted Rules Heavy.