first one is a 288 GTO (limited edition special based on the 308 but HEAVILY modified)
second is indeed a 308 GTS US version
but the third one is a GTS Turbo (Italy only version). This car is based an the 1986 328 GTS but has a 2.0 Turbo V8 (yes 2L V8!) pumping out 255 hp instead of the 328's 3.2 V8 270 hp with no turbo. Performance is almost identical though. You can tell them apart by the various inlets that help the turbo breathe.