New-wave music is out, and no one does the vogue anymore. But for nearly 20 years, Madonna Louise Veronica Ciccone has defined, transcended, and redefined pop culture. At the Study of Madonna (studyofmadonna.com), 24-year-old Jennifer Wallraff has been tracking the readership of newspaper and magazine stories to determine which era is the Material Girl's most popular. ''I originally thought...the '80s would get the most requests,'' Wallraff says. But her pseudoscientific findings peg the '90s as the hottest decade, with the brand-new '00s coming in second (despite 2000's chart-topping disc Music and this summer's sold-out world tour). No matter which era most represents the maverick Madonna for you, there's a site to get you into the groove. Here, our tour-by-tour evaluation:
VIRGIN TOUR (1985) Britney Spears was just 4 when Madonna's bare midriff, rubber bracelets, and holy-cross earrings set off a teen fashion craze. Steve Caraco's comprehensive Madonna Catalog (madonnacatalog.com/lav/lav.htm) is a testament to the mania that accompanied this seminal '80s tour (it sold out three Radio City dates in a record 34 minutes). Watch for a Madonna Wheaties box, a ''Crazy for You'' lunch box, and a ''Like a Virgin'' coat hanger buried in the site's endless parade of ''M''-orabilia. About the only thing missing is a heart-shaped photo of Sean Penn.
WHO'S THAT GIRL (1987) By releasing a movie and soundtrack -- and going on tour -- Madonna pushed synergy over the borderline. But the flick tanked, and, despite giving her a sixth No. 1 hit, sales of Who's That Girl were minuscule compared with her previous two multiplatinum albums. The Girl page at Madonna's Real World (www.tt.ee/madonna/disco/whosthatgirl page.htm) offers appropriately tinny, computer-generated MIDI sound clips.
BLONDE AMBITION (1990) The fans at MLVC.org, a clearinghouse for Madonna e-mail lists, voted ''Vogue'' her best music video. Directed by David Fincher, who was still two years from releasing his first feature, Alien 3, it fueled a dance craze that looks awfully square, given today's hip-hop choreography. Still, you can reacquaint yourself with the right moves at Instavid.com, where you can watch the full-length video instead of waiting for it to rerun on VH1.
GIRLIE SHOW (1993) The most transformative period in Ms. Ciccone's career continued with a sultry tour, sexy book, and movie (Body of Evidence) that belied her maturing business savvy. Within three years she would establish her music-industry cred by starting Maverick Records, slip out of risque and into romance with the album Bedtime Stories, win a Golden Globe for the film Evita (angelfire.com/ ls/evitathemovie/mov ie.html), and have a daughter, Lourdes. Motherhood changes everything.
DROWNED WORLD (2001) Madonna's official sites (madonna music.com; wbr.com/madonna) don't bother keeping tabs on her current tour, which hits the U.S. next week. But fansite Where Life Begins (3-x.nl/wherelifebegins) offers concert pics plus a stream of news clips, TV appearances, and rare video -- including ''What It Feels Like for a Girl,'' which MTV plays only in the wee hours due to its violence.
This decade could turn out to be the 42-year-old singer's best. But if she falters, Lourdes, her 4-year-old, is waiting in the wings -- and she's already got an adoring fansite -- come.to/lourdespumpkin.