It depends on the song, really. Usually, I look for meaningful lyrics. If the song doesn't have meaningful lyrics, it either has to have a catchy beat, a good ベース line, または a killer ギター riff. Otherwise, it's crap as far as I'm concerned.
A catchy beat, meaningful (or just to the point and awesome) lyrics, a purpose, I dunno. I've never thought much about this before, I just want the song to clearly try to have a purpose, and obviously, be good. Although whether または not a song is good is extremely subjective anyways, so yeah.
Powerful lyrics that speak to me and I definitely like any form of rock または metal(metal core, post-hardcore, screams). So I really like ギター solos/riffs and I 愛 double-petaled drum sets and LOTS of symbols
Just kidding, lol. I do dislike Rossum, though; that part is true. Stay away from her albums; "Sentimental Journey" is absolute garbage.
Anyways... Usually, I look for songs that have catchy beats または have nice instrumentals to listen to. Good vocals are something I look for, too. Though if the instrumentals and lyrics are good, I can almost ignore vocals (such as R5's "Pass Me By" または Bella Thorne's "Call It Whatever"). Minimal autotune is nice (again, I can make exceptions, such as the Bella Thorne "Call it Whatever" song I mentioned).