From my research thus far:
"If I flick on my lighter, it's an Anthem."
"When perfect strangers start hugging each other."
"A rock anthem is a powerful, celebratory rock song with arena-rock sound often with lyrics celebrating rock music itself and simple sing-a-long choruses, chants, or hooks. These Rock Anthems were chosen for their popularity as a rock anthem, music, lyrics, and originality."
"when a song demands more air guitar"
Some apparent examples:
"Anthem" - Wayne Newton
"Born in the U.S.A." - Bruce Springsteen
"Dancing in the Street" - Martha & The Vandellas
"God Bless America" - Connie Francis
"Gonna Fly Now (Theme from 'Rocky')" - Bill Conti & His Orchestra
"Hands Across America" - The Voices of America
"Heal the World" - Michael Jackson
"I Have a Dream" - Rev. Martin Luther King
"I'm Coming Out" - Diana Ross
"Put Another Log On the Fire (Male Chauvinist National Anthem)" - Tompall
"Rock and Roll All Nite (Live)" - Kiss
"Sisters Are Doin' It for Themselves" - Eurythmics & Aretha Franklin
"The Star Spangled Banner (live)" - Whitney Houston
"The Star-Spangled Banner" - Jose Feliciano
"The Star Spangled Banner" - Faith Hill
"United We Stand" - The Brotherhood of Man
"We Are Family" - Sister Sledge
"We're Not Gonna Take It" - Twisted Sister
"We Will Rock You / We Are the Champions" - Queen