…what’s the first thing that pops up in your head?
For me, an image of Master Chief from the CE days.
> …what’s the first thing that pops up in your head?
A Halo ring.
Forerunner architecture and the Ur-Didact
The Halo CE box art, with Master chief and the warthog and banshees in the background, along with the classic singing monks.
Tea-bagging noobs.
> The Halo CE box art, with Master chief and the warthog and banshees in the background, along with the classic singing monks.
Dang it, you took mine!
Master chief/Cortana.
Fast killtimes, with a predictable-but-deep spawn system, quick weapon spawns, a utility weapon great in every situation, but not always the best, a large emphasis on map control and vertical gameplay, and and a responsive strafe.
Grenade Jump suck! Why? "cause after 50 or more trys…I still can’t get the damn skull!
Halo CE/A, 2, 3, 4, Wars, ODST, Reach, and Spartan assault. 
Edit: How can I forget this, the great novels as well.
For me, when I think of Halo, I think of the experience. I really don’t have a select thing pop out in my mind.
When “Halo” is said, I think of the grand atmosphere of campaign, MM, and all the other fun inclusions.
Umm…I think of Halo. I mean, the word Halo.
Just kidding. Nothing particularly comes to mind when I think of it, but maybe it’s because I never stop thinking of it. 
> > …what’s the first thing that pops up in your head?
>
> A Halo ring.
Indeed, a Halo Ring.
> Not really a specific image, but this.
I love that scene, if only the humans/covenant against flood dynamic was explored ingame when I think Halo Legends I think this
Flying in a Warthog under heavy fire while delivering the flag carrier.
… My Spartan… I think.
I like very much how the armor looks so yeah… Or I am just too selfish
For me, I start to hear chanting monks
I think of the tracks ‘One Final Effort’ and ‘Winter Contingency’… And an image of the Halo Reach box art for some odd reason.