I have this friend who's really into social justice issues. In a sneaky attempt to evangelize, I gave him a trade paperback of Dennis O'Neil's Green Lantern/Green Arrow series for Christmas, figuring that Green Arrow's 70s-liberal-firebrand thing would resonate. And I guess it did, although I was a little nonplussed when he got back to me afterwards and said he'd really enjoyed the book, he was thinking of reading more comics, and could I recommend any other Green Lantern stuff?
Because here's the thing: while the underlying concept and backstory of the Green Lantern Corps is way, way cool on a science fiction level, Hal Jordan's always been sort of a stiff (I mean, yeah, I realize that I'm ducking several issues here, including the existence of a couple of other Green Lanterns and the whole Parallax thing; I feel ok in ducking them because a. I didn't want to confuse my friend, b. while Guy Gardner and Kyle Raynor are actually fairly cool characters, their interesting traits really only come out in team books, and c. the whole Parralax thing was really lame and is best forgotten). I'd go so far as to say that's typical of a lot of Silver Age DC heroes—they were created more to be variations on a lantern-jawed heroic archetype than to be fully-fleshed out characters who happened to wear tights (as opposed to your character-driven, angsty Marvel types). While I've always sort of liked the Green Lantern and the Flash, Hal Jordan and Barry Allen have mostly left me cold.

So there's the first reason why
The New Frontier, Darwyn Cooke's out-of-continuity reimagining of the DC Universe circa 1959 is awesome: Cooke's Hal Jordan is interesting and likable (actually, so's his Barry Allen). Still square-jawed, the Jordan who anchors
The New Frontier is an appealing mix of strength and weakness; he's a fearless test pilot desperate to get into the space program, but he's also a pacifist whose principles put him in several difficult positions during the Korean War, undercutting his sense of self-worth. This gives us the best of both worlds… we get thrill to Jordan's exploits (and it's worth noting that, for most of the book, they're Jordan's exploits, not the Green Lantern's, as he doesn't actually acquire the ring until very late in the game) while feeling like they actually mean something because they're carried out by a flawed human being instead of an animated hunk of marble. It even gives the overarching story a nice emotional undercurrent, as the gee-whiz superhero action forces Hal to work out his limits on when it's ok to fight (this territory was also mined with some success by the Flaming Lips, but that's neither here nor there).
The New Frontier is, essentially, a love letter to the American spirit of optimism in the late 50s and early 60s. In our more cynical time, this period is generally looked back upon as dopey and embarassing, and with some good reasons. But Cooke's right in pointing out that there was something awfully inspiring about a culture so naively sure of itself that it believed anything was possible if it just tried. Hal Jordan, Ace Morgan, and the other pilots who inhabit the aviation-based storylines in
New Frontier are gung-ho optimists, but the flaws and insecurities they deal with make this optimism appealing and inspiring rather than just dimwitted.
Moreover, Cooke's case for appreciating the good parts of the late 50s is far from a whitewash-- he's more than willing to acknowledge the dark side of American culture at the time, and, in doing so, bolster his argument for the good stuff (it's a lot easier to believe a good review from someone who'll point out the bullshit in his product, after all). Accordingly, the other storylines touch on the malignant elements of the first stretch of the Cold War. Batman and the Flash find themselves on the wrong end of a control-obsessed, paranoid government. Superman's and Wonder Woman's willingness to work with the system leads them to get involved in French Indochina. And, almost mirroring Cooke's point of view, Martian Manhunter J'onn J'onzz finds himself stranded in a world which simultaneously delights him with its endless wonders and depresses him with its rampant xenophobia.
The New Frontier has much else to recommend it-- the dialogue is snappy and, when appropriate hilarious; Easter Eggs for the harder-core DC continuity buff can be found all over the place (Green Arrow even shows up in the Arrowplane!); and, of course, fans of Cooke's lush, heavily-brushed art style will find themselves in heaven. And I appreciate those factors quite a bit. But, in the end, the one achievement of New Frontier which always jumps out at me is that somehow, against all the odds, Darwyn Cooke heroically made Hal Jordan an interesting character.
And they say heroism is dead.