pretty much all of the examples people are listing are in 6/8. There is a difference (in feel especially). Best way to explain it is that in 6/8 there would be 6 hi -hat beats per bar with emphasis on the 1st and 4th (most likely kick on 1 snare on 4). Which in a way is similar to 4/4 time in rap except the rhythm of the words need to be different. (You could count groups of 4 in these songs and wouldn't really feel weird about it)

If it were really 3/4 there would need to be 3 beats of emphasis per bar and would most likely be something like (kick kick snare) or (kick snare kick)or (kick snare snare). I'm sure there are some rap songs out there like this but I can't think of any. Really there aren't much 3/4 songs in popular music in general.

The only ones I've seen so far in this thread is Gang Starr "Stay Tuned" and the Ohene jawn.