Which do ya'll prefer/think works better? The first was a phase kicked off by Airplanes, but recently things have flipped over the other way.

Just a few of both to help compare:

Rappers featuring singers:







Singers featuring rappers:

singer feat. singer + rapper
such as

Till theworld ends (remix) - Britney feat. Ka$ha & Nicki

Singer featuring \rappper!

Rappers f/ Singers >>>

Singers feat Rappers usually sounds better, imo. But at the same time, a rapper featuring a singer is also kind of refreshing like in B.O.B's case.
I voted singers feat rappers, but both work out very well.

they are both good. Singers don't necessarily need rappers.

So rappers featuring singers >>>>>>>>>>

G-unit featuring Joe --- i wanna get to know you

Ja Rule featuring Ashanti --- Always on Time

Fat Joe featuring Ashanti --- What's Luv?

Kanye West featuring Sylena Johnson --- All Falls Down

Kanye West featuring Rihanna (Elton john, Charlie Wilson and Alicia keys) --- All of the lights

Jay-z featuring Alicia Keys --- Empire state of mind

Method Man featuring Mary j. Blige --- You're all i need to get by

Jadakiss featuring Mariah Carey --- U make me wanna

Busta Rhymes featuring Janet Jackson --- What's it gonna be?