In 2006, the pop singles market continued to dominate, in no small part because the pick-to-click-driven mentality of online music stores and ringtone sites gave consumers unparalleled freedom to Choose Their Own Musical Adventure. What suffered in the meantime, though, was the quality of pop/rock albums. These platters frequently spawned great singles — Justin Timberlake, KT Tunstall, the Rapture, Pearl Jam, My Chemical Romance, etc. — but didn't hold together as cohesive statements. Still, a few artists managed to churn out catchy and innovative long-players that held up over repeated listens. In alphabetical order:

AFI, Decemberunderground (Interscope): Unlike many of their dark-punk peers, AFI managed to slick up their sound without losing their batcave-and-fishnets cachet on Decemberunderground. Chalk this up to undeniable pop sensibilities and the band's knack for hooks — whether they're crafting screamo speedballs ("Kill Caustic"), space-age synthpop ("The Missing Frame") or tundra-chilled gothic landscapes indebted to the Cure and Damned ("Summer Shudder").

Blood Brothers, Young Machetes (V2): The Blood Brothers' slobbering, shrill, twin-vocal assault and nuclear-bomb riffs frequently feel plucked out of a Stephen King horror movie. But on Machetes, the Seattle band's Dali-esque abstract imagery and unhinged mania coalesce into shockingly linear pop songs. "Linear pop" is a relative term, though, as their post-punk/no-wave/hardcore hysteria remains very much intact: "We Ride Skeletal Lightning" lurches like a zombie jonesing for brains, while "Spit Shine Your Black Clouds" is a danceable conclusion to PiL's shuddering death-disco.

CSS, Cansei De Ser Sexy (Sub Pop): With Le Tigre on hiatus, the Brazilian sextet CSS stepped up for booty-dancers, staunch feminists and electro-pop fanatics everywhere with their high-energy debut. "Let's Make Love and Listen to Death From Above" begs to be blared during a Jazzercise class for hipsters, "Art Bitch" sounds like a deconstructed Yeah Yeah Yeahs song stitched back together with diagonal big-beats, and the bubble-bath-synth groover "Fuckoff Is Not the Only Thing You Have to Show" resembles Ladytron trash-talking with Cyndi Lauper.

Def Leppard, Yeah! (Island): Critically maligned arena-rockers Def Leppard sure sound like they have something to prove on their fantastic covers record, Yeah! And who can blame them? They've always drawn inspiration from seminal UK glam and metal bands, but can't seem to escape being seen as poof-rock hacks. Which is too bad, since their faithful (but not derivative) renditions of classic cuts from Bowie, T. Rex, Roxy Music, Sweet, ELO and even the Kinks — in the form of a gorgeous, copper-burnished "Waterloo Sunset" — more than cement their musical talent.

Nelly Furtado, Loose (Geffen): Furtado, who's notorious for being a hit-or-miss performer live, is perhaps the year's biggest example of how studio gloss and the right production team can revive (and reinvent) an artist's career — and create Top 40 gold in the process. Loose is the most consistent and innovative pop-diva disc of the year, from the Latin-flair of "No Hay Igual," digi-funk bodyrocker "Maneater," and of course, the playful �80s-glitter all over the Timbaland-featuring synth-swerve, "Promiscuous." - ANNIE ZALESKI

Look for Part II of this article in tomorrow's blog!