My favorite B&W developer is Ilford's DDX. It's liquid so it's easy to mix and when stored in glass bottles it lasts a really long time. Also it gives the best film speeds of any developer I have tested. I have done BTZS film testing with DDX for 100 T-Max, 400 T-Max, HP5+, FP4+ and Fuji Acros. For very high contrast scenes I use DI-13 with 100 T-Max. This developer was designed by Phil Davis and maintains good film speed. All my sheet film is processed in Jobo Expert Drums at 75 degrees and DDX is diluted 1+9.
Fred