Sad songs is probably the gayest way you could have put it...
If you talkin about deep/hearfelt shit, then yeah, why not. Rappers use to do a few songs like that every now and then back in the 90s and if it was real, they didn't get clowned for it. 2Pac, E-40, Ice Cube, 4-Tay, Seagram, etc. had songs like that...
And as far as love songs... A lot of rap love songs tend to come out as bullshit. Id rather not listen to some fake ass Ja Rule & some random R&B chick type of songs.