OK the first and only Sentra SE-R(AKA classic) Was from 91-94. It and the NX2000 were the first SR20DE powered Nissans in the US. Some say they were the fastest SR20DE powered car made to this date because they were lighter,had the least emmsions garbage on them and had fatter cams. The NX200 also ran from 91-94 and then it was discontinued.
In 95 they came out with the 200SX SE-R. Also powered by the SR20DE it was thought to be a bit slower than the Classic because it had more Emmisions stuff,diffrent cams and a new low port head design. The 94 Classic also had the new low port head design but its faster because....it is a classic
The 200SX SER ran untill 98 then it was discontinued. Also the 98 MY the 200SX lost the LSD trans.
The 98 MY also brought a 4 door SR powered car
The 98 Sentra SE! Witch altho being void of having a lsd trans is the best one IMHO. The 98 SE ran through 99 and was remodled with the car your driving now the 00 or 01 Sentra SE.
That just about sums it up. I think...