Compressors: necessary or not?

[Timo]

I like compressors on busses to 'gel' several individual sounds/parts into one, or to get them to sit nicely with each other. Or to shape their transients or add sustain if needs be. I also sometimes quite like the rather unconventional method of placing a reverb before the compressor, it really gives it loads of depth if used sparingly.
I also like using multiband compressors almost as a dynamic EQ.

Quite like the un-subtle aspect of compressors, and haven't really found many software compressors that 'pump' easily. The only one I use in that sense is Cubase's own rough n ready 'VST Dynamics' plugin.