best preamps

Sorry, but I don't think your question is a good one. There is no "best." If there was, all of us would own the same brand of preamp!

The latest McIntosh C52 is a sleeper. Remember you have to use the included equalizer  to compare with other more ´´ tiped up ’´ preamps out there. Makes a good match with brighter speakers like Focal or Magico.

@jhamond987 

When you said unlimited budget, how far do you want to go? Are you looking to get just the linestage preamp or the entire setup and system? What are your current setup and system? Did you already have a setup or trying to start from scratch? 
Without knowing the rest of your gears, If you already have a setup, it's hard to make recommendations. 

I love my McIntosh C2200! Used under $3500. 

Unlimited budget means a call to CAT, MBL, or dartZeel... they can hit $100k if you want to burn some cash