Here's my favourite commentaries from 2 years of researching 1 Corinthians, I've used plenty of others but these are the ones I keep coming back to.
Gordon Fee, The First Epistle to the Corinthians, NICNT, 1987
Fee is always good value and what is good about this commentary is its evenness of approach and his tendency to argue everything clearly point by point. You are never left wondering, how did he get here from there? This makes him a good converstaion partner, especially if you want to disagree with him!
Anthony Thiselton, The First Epistle to the Corinthians, NIGTC, 2000
Thiselton can be a little frustrating and every esoteric subject is explored in intimate detail, but this is really the strength of this book. Its extra sections on selected issues are especially useful, his cross-disciplinary engagement is nigh on comprehensive, and his own translation is idiosyncratic enough to be interesting.
David Garland, 1 Corinthians, BECNT, 2003
This commentary can be a little cumbersome in places but is a favourite for very useful engagement with other 1st century literature and for not being afraid to depart from the beaten track. If you need another opinion, Garland is your man.
Jospeh Fitzmyer, First Corinthians, AYB, 2008
Fitzmyer's engagement with the text is terse and sometimes indecisive, a positive and a negative depending on circumstances, but the bibliographies at the end of each section are indispensable. His introductory section is also essential reading.
Anyone have anything else to add? Sins of omission or points of contention?