We had a series of mic "shoot-outs" while I was staff at East Iris Recording Studios in Nashville. A pair of Neumann/Gefell m582 omni's won hands-down in every test: Piano, strings, guitar...
Of course, omni's like these require a nice room. http://www.eastirisstudios.com/studioa.html
I guess I'm attached to a very nice compressor from the '70s called a Urei 1176LN Blackface Compressor. I personally don't have one, but I use them when mixing at a friends' studio in town. WICKED piece of gear. When it comes to my own gear, I'll go with my Rode NT1A. Cheap mic (about $300 CDN I think) but man, it sounds good - very quiet and very true.
I'll drink to that....and maybe a few more times just for the heck of it. It actually works pretty well on vocals as well...my most recent single has it all over the vocal tracks - it actually gives me the ability to listen to myself!
For vocals, try to get your hands on an LA-2A... Universal Audio is building a "reissue" of the original that sounds nice; of course, the original LA-2A is supreme. Even an LA-3A would be nice.
A really great buy, and great bang for the buck is the Avalon VT-737: mic pre, parametric eq, and optical compressor in one box under $2k.
Don't disregard LA4's - they are really nice as well. I have two as well as a couple of the 1176/8's. One that no one ever seems to mention is the Aphex Compellor which can be pretty darn transparent - unlike the ones already mentioned.