Trim Levels
I am not too familiar with the older models of the 4Runner, but it is safe to say that the "Limited" is going to be the top trim level. I'd bet that the SR5 used to indicate a step up, while the Limited was the loaded version.
I have a 2005 SR5, which is now the 'base' model. The middle 4Runner is the Sport Edition, while the Limited is top dog amongst 4Runners. Even my SR5 is hardly 'base' at all, since it has power everything, 17" alloy wheels, power moonroof, rear spoiler, cruise control, automatic climate control, etc., etc.
The Sport Edition comes with different rims (which I think do not look as nice as the ones on my SR5), different seats, firmer suspension and some cosmetic changes (silver roof rack, body-colored mirrors, fake hood scoop, etc., etc.).
The Limited gets you leather seats, navigation system, better stereo system and a few other things; but it comes at a nice premium on the price!
One thing is certain, though, most everyone on this forum thinks that their 4Runner is great and each of us chose our drivetrain, engine, color and trim level for different but equally important reasons. I probably like my V6 SR5 4x4 just as much as someone else here who forked over a few extra g's for a 4x4 V8 Limited.
It is nice to see some of these 'vintage' 4Runner photos here, too. These trucks just never seem to go out of style - even the ones that are approaching fifteen years of age! Let's see a Ford Explorer or Jeep Cherokee pull such a feat without looking very dated.