The 1991 Nissan Sentra SE-R with the 2.0L engine has been, hands down, the best vehicle I have ever owned. It is quick, agile, and extremely reliable. It currently has 261,325 miles on the engine and continues to run strong.
The only area I did not give five stars was comfort, the back seats are definitly "sprots car" back seats. They are cramped and there is no such thing as leg room, but if you're not the one riding in the back, there is no problem with the front seats, they are comfortable.
The biggest downfall of the Sentra is what is known as "5th gear pop-out". The manual transmission can develop a problem where 5th gear will pop out and into neutral when under strain.
I have only done two repairs to this car so far, the fifth gear pop-out and a water pump. It is excellent on gas (average 30 mpg) and is always fun to drive. The engines are know for their durability and reliablility. I hope to have this car for many years to come.