Which of these 35mm camera's are best?

I need to borrow one from my University.

In Alphabetical Order:
-Centon DF-300
-Centon K100
-Nikon FM3A
-Pentax K1000
-Pentax ME Super
-Pentax MZ-M
-Vivitar V3000

Added (1). Are any of you basing this on the actual camera specs, or just the brand name?

Added (2). Because I too can go "Oh, look a Nikon i've heard they're good" but then I've also heard that for 35mm cameras Pentax were way up there

Nikon is the way forward my friend… But that's just my opinion i suppose.

I'd go with the Nikon as well.

Me too!

Based on the actual camera specs the Nikon is the better camera. It was built to professional standards and has probably withstood the test of student use better than the others.
http://camerapedia.wikia.com/wiki/Nikon_FM3A

A more important question is whether you know how to use a camera properly…

if you are new, it really doesn't matter which camera you use…

the important factor is your skills, knowledge and experience of film photography…

without the correct skills, the make and model are immaterial…

and what lenses you got to play with?

The Pentax K1000 is a legend when it comes to the later half of the film dynasty… I'd say its your best choice…

It has to be the FM3A, it's a serious manual camera. The ME Super perhaps is on the old side now, but would be reasonable too, K1000 is a serious Pentax, but is a little chunky.

The Pentax ME Super were fantastic cameras in their day. Most models are well over 30 years old now so you can pick them up very cheap on ebay and the quality and ease of use is pretty good. But as has been said over and over Nikon is pretty much the way forward with modern cameras. However, one camera you didn't list was the Canon eos 1V pro. This is a fantastic 35mm camera.