Yes. If I’m in the mood to sing along and know the lyrics, I sing with whoever’s singing–not neccessarily in the same octave they are singing.
Gender is neither here not there. I sing along when drunk and / or alone.
Anything I know the lyrics to, I’ll sing along. Sometimes, if I don’t know the lyrics, I’ll just fake it. 
Absolutely. I’ve got quite a wide range, so I like to try to match the female singer’s voice without going into falsetto. Joni Mitchell is a particular challenge.
Yup, if I like the song. Sometimes I need to take it up an octave or two, of course, but I’m an alto; I need to take a lot of soprano parts down an octave so I don’t hurt anything.
Yep!
I tend to sing along with male voices better than with female voices, because I have a deep voice and I hate singing in falsetto. I have found that if I try to sing along with a female singer, I instinctively jump down an octave. It feels more natural that way. Which is embarrassing when I’m within earshot of someone, since they probably wonder why I’m singing like a guy.
Also, when I sing along with lyrics written for a guy, I often forget to change swap out “girl” for “boy”. That probably causes more raised eyebrows, but I don’t care.
Oh, yes. I sing along with anybody, torturing those unfortunate enough to be within range. I can’t carry a tune and may as well be tone deaf, but if I like the song, I’m singing along. My husband must love me very, very much to put up with that. 
I’ll sing along if I like the song, whoever sings it, harmonizing if I can’t get my contralto around it, but walk a mile in my shoes and experience Drachillix going diva, channeling Mariah. Or Whitney. Or Toni Braxton.
He has no shame because he is* fabuous.*
Ditto. If I know the words, I sing with it. I like to build harmony parts for songs too. I resent having to have music on so low that I can’t sing along at a comfortable volume, so I sing on Saturdays, home alone, or in my car, or when tipsy.
Usually no, but when driving and listening to Lida Husik I play guitar in my mind along with her.
Yep
I’m quite famous for my baritone rendition of Fur Patrol’s Lydia.
All the time. If I know the words, then I sing along.
Most popular female singers are sopranos.
I am, well, not. (As far as I can tell, I have the same vocal range as Billy Joel. We even break at about the same point, around the A above middle C.)
I will sing along with anything; I prefer popular music done by male singers, because it doesn’t require working the octave or harmonising to pull it off.
Of course, why not? Plus, I have a very low voice, so the notes are generally very easy to hit.
But I’ll sing along with any pretty much anything - and just switch to my octave when it pushes a bit too hard.
During duets though, I’ll generally sing along with the female singer.
Yep, I’ll sing along to anyone, male or female. Hell, I’ve even sung along to Leonard Cohen. It’s harder, though, on his later albums because he sings so low now.
I’m an alto who loves rock’n’roll. Most of the songs on the radio have male leads, so of course I sing along. Sometimes I adjust the lyrics to suit my sex; sometimes I don’t. (On Journey’s Separate Ways, it’s about 50/50 whether I’ll sing “If she ever hurts you” or “If he ever hurts you”).
I can do a perfect Biz Markie.
I’ll leave it at that.
Whereas I used to do a fine rendition of Wuthering Heights. But I did have to use falsetto.