Well, for starters you just compared 3 totally different types of cars. The 300zx has the biggest engine by far, but it is also the heaviest and therefore is usually tuned for straight line power. It's the fastest of the four in stock form. The 240sx and the Celica are fairly equal in stock form, but the KA24/SR20 engines have been proven to handle power better and combined with the RWD setup (vs FWD Celica) the 240sx is easier to tune. I happen think the 240sx is more fun to drive because it is much "torquier" due to the higher displacement (2.4L vs 1.8L) and oversquare design, but this also gives it a lower redline and less peak horsepower. Celica is definitely the most reliable as well. And finally, the Del Sol (del slow?) is a civic with an inferiority complex. I've never really understood the appeal...