I've owned a well used '98 Prizm for for over six years now and at 166K it still runs and does not give me headaches. The mileage is great, I can go almost a whole month without refilling the tank. Heater and AC are strong and quick to action. However it handles poorly, becomes shaky, and burns huge amounts of oil at high speeds, so avoid the interstate. May get water into engine if roads are wet enough to puddle. Interior is very cheap, with some parts snapping or peeling with age. Door handles WILL eventually bust. Steering wheel module and shifter unfortunately made of very soft materials that easily scratch & collect dirt or hand gunk. I have had to replace rear shocks, power steering.
Personally I like it appearance wise, not too boxy or zany. Sleek, Japanese look. (basically a Toyota Corolla inside and out) Very fuel efficient and has more cargo space than appearance suggests. Previous owner actually destroyed the starter and burned out the engine yet it was fixed with no further problems. I think you could drop the thing off a cliff or remove parts and it would still run. I have not had any significant or very expensive problems with it, it has never stalled, overheated, or broke down. Very good at sharp turns, very few blind spots.
As far as used cars go, very good. It will be a loyal and low maintenance servant for many years if you can find one that wasn't abused.
People either love the Prizm or hate it. My take away is it's not a terrible car. It's really not a great one either. It could have been built with better quality components concerning the body paint, shocks, and interior plastic components. The typically 90's low ride of it makes it prone to issues involving rain or floods, so take caution by driving a bit slowly and avoiding large puddles if the roads are wet. Even a small amount of water can make the engine protest or worse.