These have yielded my best results for LEAD vocals: Waves Ren Compressor (start with Vocal preset for a singing style vocalist, the Crunch setting for a rap/rage against the machine style), C4 Multiband compressor which is great for deessing while compressing (and basically using it as an EQ), The digidesign compressor (really, this thing slams, is great for drums, and always seems to get passed by), Compressorbank, and Bombfactory's LA-2A (rarely the 1176) , and TC Voicestrip. I'd have to rank them in that order for vocals, but it always depends on the song & what you are trying to achieve. On top of all this, if you are looking for "In you face", be careful not to leave all the work to the compressor & overcompress. Do vocal rides as needed. Some vocals need more help than others. Another trick you can do that's more of an autovocal ride is to put a gate on the lead & duck it (not TOO much) to a key of a conflicting musically track such as guitar.
On Backgrounds, I'm a total Fairchild whore. I has become my new BG chain. The ren. comp, compbank, c4, and la-2a also sound great.