Family Guy vs Simpsons?
Pat Boone vs. Little Richard.
Heh. I have a tape of them doing Tutti Fruitti together. Boone pretty much gives up by the end.
Never Mind.
I was going to say U2 vs. REM, but I think yours is better.
Andrew Lloyd Webber vs. Stephen Sondheim
Sometimes on theatre boards that gets very ugly
Seriously, that seems to me to be somewhat close.
Not Kelly vs. Clay (they’re different seasons, shuh!) but whatever this year’s crop is always brings up arguments.
Kelly vs. Justin
Clay vs. Ruben.
If you’re talking about popular music being debated, AI is the most prominent forum now.
The OP brought up Britney vs. Christina. That seemed to have bigger legs than a lot of these mentioned.
But, since Idol started, it has unquestionably dominated the area of musical argument.
Radiohead vs. Wilco.
I was going to say Radiohead v. Coldplay. Maybe it’s Radiohead vs. everybody!
N*Sync vs Backstreet Boys?
Old folks can’t tell the difference between the two. Young girls drool over both and pick their favorite boys. They sell a bazillion records.
Of course, this would be the early 60’s Beatles/Stones debate. Not saying that those “boy bands” ended up taking the same paths 
Quite so.
Watching the remaining half of the Who headline at Glastonbury makes me think current groups are simply not up to that standard.
Guns N’ Roses vs. Nirvana.
Nah, those two weren’t really contemporaneously popular. G ‘n’ R were at the end of their days when Nirvana were beginning to gain popularity. In my grammar school, the heavy metal/hard-rock camps fell into two categories: Guns ‘n’ Roses and Metallica.
Nirvana and Pearl Jam would certainly be more apt comparisons for the early-to-mid 90s and I think more closely reflect the Beatles v. Rolling Stones dichotomy. Today, though, I really think the music scene is way too fractured to have such a megalithic competition between two super bands.
I think Wilco vs. Radiohead is the best one so far.
Everything was better when you were young.
Watch a performance of Baba O’Riley from this last tour. Come back and tell us how much better the acts of today are. The half-dead Who still stand up to any live act today.
Ruben Bolling explains a lot…
Radiohead vs. Flaming Lips is one that also came up a lot in the late 90s/early 00s.
None of the contemporary bands named so far are even remotely close to the Beatles in terms of influence and impact on modern popular music, or even as important, relatively speaking, as the Stones, who (IMHO) are well behind the Beatles in historical importance. Even U2, who are rightly considered one of the great bands of all time and who’ve made a dozen or more songs I adore, are way, way behind the Beatles.
SINCE the 1960s, I think the only really interesting contemporary this-or-that matchup, where you had (a) clearly defined camps that liked one or another and (b) two huge, huge and important musical acts, was Michael Jackson and Prince in the 1980s. Michael Jackson - it’s easy to forget this because he went insane and is now a freak show - was popular to an almost Beatlesesque degree in the early to mid 80s, made awesome music, and was a pioneer in modern pop and, especially, the eme3rgence of the music video. Prince was the other alternative; more versatile and risk-accepting in some ways. Rolling Stone picked him as the Artist of the Decade for the 1980s over Jackson, a choice I find bizarre but it shows you how important he was.
Since then there’s not really a comparison. You can find a lot of this-or-that choices but none who were truly HUGE.
Nirvana and Pearl Jam is an interesting choice, but by the time they rolled around, the really innovative music wasn’t two-guitars-a-bass-and-a-drum-kit rock. It was rap and hip hop. The Beatles were at the cutting edge of innovation in popular music, the Stones less so but still making amazing and innovativbe rock music in a time when making rock music harder was the cutting edge of popular music. (The bridesmaid here is the Beach Boys, I guess.) Those acts, fed with a little folks tradition, lead directly into Led Zeppelin, Hendrix, Janis Joplin, the seven hundred bands Eric Clapton was in, and so forth.
Is that true of Nirvana? Pearl Jam? Nah; REM, Radiohead, and Samshing Pupkins delivered more innovative sounds to mass audiences, don’t you think? For innovation, being at the cutting edge of music, I’d rather have Public Enemy, OutKast, and Lauryn Hill.
Nah. I saw the Who live (in the 80s, but still), and I’m a big Who fan (up to Who’s Next, at least), and I’ve seen dozens of bands that were just as good or better, both in terms of songwriting and performance. Husker Du (and Sugar), Sleater-Kinney, Fishbone, The Feelies, Yo La Tengo, Midnight Oil, even U2 and R.E.M. (admittedly both back in the 80s, too) all blew The Who away live, IMHO. It doesn’t take anything away from one act to admit there are other artists capable of delivering the same intensity in their performances. I always think it must be sad (not to mention a bit reactionary) to believe all the “best” cultural moments have passed. But every generation seems to have more than enough members who believe exactly that.