The Nissan Maxima is one of the best used car deals out there, provided you find one that hasn't been beaten into the ground, and you can pry it from the owner's hands at a reasonable price.
There are a few different styles of Maxima:
First generation: 1982?-1985
Second generation: 1985-1988
Third generation: 1989-1994
Fourth generation: 1995-1999
Fifth generation: 2000-
Both the first and second generation Maxima's were rather unattractive and boxy. The first gen was rear wheel drive and produced under the Datsun name. Second gen's were front wheel drive and most labeled Nissan.
Third generation Maxima's are available in great abundance, usually with high miles. Two trim levels were produced: SE and GXE. The SE was the more sport-oriented version, coming with a 190 HP V6 and available 5-spd manual transmission. The GXE had a 160 HP version and was available in automatic only.
Fourth generations are possible the most popular design of Maxima, probably due to the rounded edges and high reliablity.
Fifth gen's are the newest. The $25,000 shiny sedans you see tooling the streets. Given the choice, I would invest my hard earned money in a fourth gen. The 3rd gens have too many problems while the 5th gens are too new to be affordable. But alas- I have a 3rd gen, and I will love it until the day it no longer moves under it's own power.