Ive had a Keeley AND a diamond and built about ten other types myself in my quest for the "perfect" compressor.
There are two different types of compressors the standard dynacomp clone and the optical compressor. Some with clean blend "parallel compression" some without.
IMO the key to finding the right compressor for you is to FIRST decide which attributes your looking for.
If you want squishy, rubbery, or snappy attack; a compression effect that is entirely noticeable go for the dynacomp type compressors, the Keeley being the best of them.
If you want transparent "cant hear it when it on, miss it when its gone" dynamic range control go for an optical compressor, the diamond is a great choice but there are many others, start google-ing.
once you've chosen the type of compressor then youll have to decide whether you want one capable of parallel operation or not. I find this more useful with the dynacomp type compressors, it allows you to restore some of the original attack even at higher comp settings.
good luck compressing!
here is a great place to start looking:
http://www.proguitarshop.com/index.php?CategoryID=40
what's a good compressor pedal to use with it? I have an Analogman modded Dynacomp, but it's way to vintagey for this task.
I have two
