No thought required....Chinook seat by far. With adjustment up/down, forward/aft and tilt....combined with adjustable pedals and adjustable cyclic....what more could a guy ask for! Well maybe Arm rests...and a tray holder and place to stash yer Tea Cup!
Worst....anything Bell especially the 206 series.
The 205 seat....if the webbing is adjusted just right...is ok. If not....it would make one volunteer for the Infantry!
Most enjoyable was the Sikorsky S-58T....because of the big ol' sliding door next to your bum....that let you look down from a great height at the SLF!