Excellent turbo years are 91 and 92. These are the quickest and best equipped
turbos, outside of an Aero. Quickest because they have the 2.3 liter engine, full pressure turbo, no Traction Control Systems (it was optional in 92, so beware) and the final drive ratio was lower than the later Aero cars (the 91/92 turbos are said to be slightly quicker at the bottom end than the Aero, while the Aero is faster, smoother and quieter, due to its higher gearing). Best equipped because they had the Aero three spoke 16" wheels and the stiffer Aero suspension. After 92, you have to pay for an Aero to get any part of an Aero.
An excellent year for the Aero is 95. The Aero has the wheels, 225 horsepower (vs. standard turbo's 200 - the automatic Aeros have the 200 hp engine also), some aerodynamic body cosmetics and some of the sexiest production seats ever made. 94 is a good year, but beware the 93 Aero, as TCS was mandatory and unswitchable, although a switch kit is offered.
For non turbocharged models, look for the larger 2.3 liter engine, which started in mid-'90.