Compression has it's place. I'd of been kneckered without it mixing a band I recorded the other week, one moment the singer would be at talking volume, the next we could hear her through the soundproof doors.

Being a fan of harsh EBM i enjoy compression on vocals in electronic music

here's the way i use compression i just use it sort of like a customizable normalizer, i want dynamics but i want the dynamics to peak exactly under 0.5 decibels (my personal standard)

Brickwall limiter is best for that.. but it's basically just a compressor with no makeup gain and a hard knee and super high ratio.

My standard is -0.5
I wouldn't recommend going over 0 in any scenario, as that's when digital clipping occurs, assuming you're using a music program or some other digital equipment.

actually i meant it negative, in my compressor the negative sign is already there

too much compression is not a good thing. its hard to listen to mixes now of different artists just because of the volume differences in the songs that are super compressed. not to mention how much it takes away from the sound of the song. between the low quality of mp3s and super compression some songs just sound horrible.

i would rather listen to a 48kps mp3 than an over-compressed wav file
and i actually i do (it's bright eyes -"Blue Christmas" even at 48kps conor still sounds awesome)