I personally like the 89-90 (Pig Nose) but thats me, and I pretty much would take any year 240 based off style alone.
If I where to buy a new 240 what i would look for would depend on 2 things. One is how often i would be driving, and what kind of driving i would be doing.
For a car to drive to work, and race on the weekend i would take the cheaper but still solid S13. If it was a car for around town driving i would rather have the newest car i could get so 97 or 98.
If i where to get the S13 i would get the coupe base off slightly lower weight, slightly better weight split, and slightly stiffer chase then compared to the hatch. Dont get me wrong i love my hatch, but i also own a 93 coupe base model that will become the car that gets modded because it is a better base (at lest for me) to begin with.
So my recommendation is get what you light and can afford
Black 1990 FB
KA24e Built for Turbo /w other bolt-ons here and there.