One of my favorite classic compressors is the GATES Sta-Level, and the GATES Level-Devil. These compressors are sha-wheat on lead vocals. The Level-Devil does a Exp/Comp thing that's hard to imitate with any other gear. Another fav of mine for electric guitar are the cheap arse DBX163X. 1 slider- one way for more, one way for less. I pick up some of these on ebay for $50 each & really sound good.