Equal parts John Hughes and John Carpenter, Zombieland perfects the romantic zombie comedy elements of the good, but insanely overpraised, Shaun of the Dead.

Shaun veered into melodrama when endangering those at whom audiences had been snickering. That Zombieland’s climactic sequence takes place in an amusement park — coincidentally the first time a film has successfully pulled that off — is fitting.

Much like a rollercoaster, Zombieland is a loosey-goosey exercise in controlled fear and nervous laughter — only with Woody Harrelson, Jesse Eisenberg, Emma Stone and Abigail Breslin battling zombies. (Yes, there’s convincing danger, but their characters are, after all, among the few to survive thus far, so give them credit.)

As rambunctiously funny as Zombieland is, that’s not to say it’s without weight, given the acting chops, screenwriting flourishes and director Ruben Fleischer’s discretion with drama.

Zombieland has one of 2009’s best opening-credits sequences — a glorious slow-motion tableau of terribly messy blood, vomit and bullets set to Metallica. It’s post-apocalyptic and postmodern all at once, just like the rest of Zombieland.

Eisenberg is Columbus and Harrelson is Tallahassee — neither their real names but instead their hometowns. (Tallahassee lays out this rule to avoid too friendly a connection.)

A multi-phobic college hermit, Columbus serves as the film’s makeshift travel guide. After all, a loner dweeb incapable of attracting anyone would survive a zombie outbreak – leading to a fine satirical trope in Rhett Reese and Paul Wernick’s script.

Columbus lays out the rules for survival — advice of cardio training and a double-tap killing method, among others, which amusingly appear as onscreen graphics. He’s certainly learned the hard way — as seen in a sequence proving Zombieland won’t skim on splatter elements. All splintered bones and bloodcurdling wails, it’s an undead variation on The Bourne Ultimatum’s bathroom fight with a nerd at its core.

After years of roles as the odd teen out, Eisenberg has settled into playing earthy, earnest men of words. As he did in Adventureland (which Zombieland resembles, with brain-eating), Eisenberg ditches menschy mannerisms. Here’s he convincingly plays a man grappling with an amusing central question: Can one learn to live when surrounded by the undead?

Comparatively, Tallahassee is an alpha-dog zombie-killing machine with one known weakness – the Twinkie. (They do have an expiration date, you know.) Harrelson is a double-barrel hoot with a Snake Plissken vibe — enough so to swap out Cheers as what will be his iconic role — but also elicits genuine regret when discussing his pre-zombie life. (Fleischer shrewdly doles out flashbacks for all the main characters.)

En route to see if Columbus’ family is still alive, the duo meets up with Wichita (Stone, of Superbad) and Little Rock (Breslin, of Little Miss Sunshine) — “sisters” who’ve subsided by scamming trusting humans. Reluctantly pairing up, the quartet journeys west toward an amusement park believed to be a zombie-free zone.

With bangs and a scowl to rival Lily Allen, Stone gives Wichita a husky-throated sweetness and gravitational sexual pull that lures Columbus. It’s time she gets a lead role in a comedy already.

If anyone gets short shrift in the cast, it’s Breslin, although Little Rock’s lament in a zombie-riddled world — being deprived of an enjoyable childhood — is more abstract.

Zombieland’s setpieces take place on backwoods or local roads leading to small-town grocery stores, chintzy tourist traps, the aforementioned rundown fun park and, at one point, a vast mansion. (That stop involves a surprising cameo and a scene so riotously and transcendently conceived that it’s one of the decade’s funniest.)

That keeps with Zombieland’s jocular, practical sense of never being too arch or too serious, as does the soundtrack, which includes Sea Wolf, Band of Horses and Doves with a bit of Van Halen and Johann Strauss for good measure.

Fleischer tells Zombieland’s story with an equal knack for visual flair and effective performances. Even at his most worrywart moments, Columbis is proactive — as is everyone else — and the film legitimately sells facing fear, taking a stance and being brave when a life is on the line that’s not your own.

Never too preachy or anarchic, but always a blast to watch, Zombieland is one of the decade’s best comedies and, hands down, its best zombie film.