"Orion" by Metallica - I think it's only the one "slow" part though, but I'm not sure.
"Manic Depression" by Hendrix Probably my favorite Hendrix song
"Obscured" by The Smashing Pumpkins I've never heard this at all, so no comment.
I never pay attention to the time signatures of the songs since most bands don't use written music and some bands just use really weird time signatures or have lot's of time changes, so it would be hard to keep up with.
And if you could explain a little more on what 3 4 time means in rock music I could try to help.
In written music, there are whats called measures or bars. Each bar contains the time signature specified number of beats. What the time signature does is denote A) how many beats are in a bar and B) which note counts as one beat. The most standard time signature is 4/4 time. Which means that there are 4 beats in one bar and a quarter note equals one beat. If the signature was 2/2, there would be 2 beats per bar and a half note equals one beat. In the case of 3/4 there are three beats per bar and a quarter note equals one beat.
So it's actually kinda difficult to tell what the time signature for a song is without seeing the actual written music...especially if you can't read written music.