iHeartRadio Music Festival: The Best and the Boldest

Most Emotional Moment: Lady Gaga
What's a Gaga performance without a dovetailing social campaign? She dedicated her heartfelt independence anthem ''Hair'' to 14-year-old Jamey Rodemeyer, a fan who recently committed suicide after being bullied for his sexuality. When she exhorted the crowd, ''Let's do this one for Jamey,'' there wasn't a dry eye in the arena.

Best Comeback: Jennifer Lopez
On the short list of diva essentials: shirtless male dancers, a red-hot fringe-and-feathers getup with bedazzled cane, a golden throne. Lopez brought that and more, pulling out all the sexy stops for her dripping-in-decadence set, which included hits old (''I'm Real,'' ''Jenny From the Block'') and new (spring '11 smash ''On the Floor'').

Wildest Entrance: Nicki Minaj
Leave it to the queen of hip-hop outrageousness to inject a little extra flair: The raptress rolled on stage via a dolly, Hannibal Lecter-style, sporting white-blond Afro puffs and accompanied by a cadre of demented-doctor dancers — and then tore through ''Roman's Revenge,'' ''Moment 4 Life,'' and ''Super Bass.''

Kookiest Threesome: Steven Tyler, Nicole Scherzinger, and Randy Jackson
Despite working for opposing singing-competition shows, the two American Idol judges played nice with The X Factor's Scherzinger, serving up a silly-fun performance of Tyler's ''(It) Feels So Good,'' with Jackson on bass.

Biggest Country Star: Kenny Chesney
Carrie Underwood and Rascal Flatts brought their A game, but Chesney hog-tied them all with his high-octane performance, which included catalog favorites ''Beer in Mexico'' and ''Somewhere With You.''

Sweetest Cover: Bruno Mars
Like he did at August's VMAs, Mars sang Amy Winehouse's ''Valerie.'' Even with the slight sense of déjà vu, his rendition was a standout in a hit-filled set (''Grenade,'' ''Just the Way You Are,'' ''The Lazy Song'').

Best Gymnastics: Coldplay
Frontman Chris Martin dropped to the ground for a spontaneous somersault during the rousing close of ''Viva la Vida,'' then pleased fans further with melodic new single ''Paradise.''

Odd Pair Out: Karmin
Every act on the bill has had chart-toppers except the coed duo, who made their mark via covers on YouTube. So their inclusion on the roster seemed to garner a rippling ''Huh?'' from the crowd when they performed Minaj's ''Super Bass'' and Chris Brown's ''Look at Me Now.''

Hottest Surprise Guest Star: Usher
French DJ David Guetta's spin through recorded versions of his hits — including ''Where Them Girls At,'' ''Memories,'' and ''When Love Takes Over'' — was a little sad sans live vocals from the songs' guest artists. That is, until Usher popped out unexpectedly to deliver their high-impact collab ''Without You.''

Strangest Omission: Alicia Keys
Her velvety set ran through a driving ''No One'' and the debut of wrenching new track ''A Place of My Own,'' but something was missing: ''Fallin'.'' Fests like this just require the signature songs. Blessedly, Keys atoned by returning to the stage with Jay-Z for the anthemic ''Empire State of Mind.'' Forgiven!