I think its amusing you can tell when people actually started playing the game by their map preference. I started with lan parties on haloCE. They worked great for that but I'm not sure I'd recommend any of them directly to be ported to 4 as I've never played them on matchmaking.
Personally I cannot understand what the obsession is with remaking a map and making it bigger every time. Or for bigger maps in general. They are fun for btb only, and I cannot stand 4v4 in most of the designated "small team" reach maps because they're just so damned large. esp with ar starts. Just look at reaches versions of ivory tower, midship, and lockout. you could almost fit 2 of the original maps in each of the remakes... pass... Ironically I think all of the "4v4" maps would be the most fun in btb.... sigh...
The sad thing about the large maps is, from the stock release maps, only hemorrhage is a fun slayer map, the rest were maps made for the campaign that can sometimes pass as an objective map.... and even then spire is just awful all around.
I know its more than three... but..
For objectives and btb slayers I would bring back burial grounds, relic, and Zanzibar. I think bg/coag/hemorrhage has evolved into about the perfect map... I think that map would be absolutely zero fun if they kept the super large bases and banshee spawns, esp given the current version of the banshee.
I'd also bring back wizard/warlock, turf, and the small/original versions of lockout and midship.