#1 is money for obvious reasons, I gotta fund uni and social life and so on somehow
#2 environment + people because a shitty workplace and cunts for coworkers is not going to be made better by being paid a lot
#3 job security, this is a big one for me and I would venture to say that if I was in a shitty job I would not leave unless I was totally sure I had something else lined up first, I learned this the hard way
My job atm has 1 and 2 covered, and probably 3 as well except that since I'm casual obviously they can change around my roster however they please. Which I accept.
edit: obviously I'm talking about part time jobs while studying here. When it's your chosen career its a bit different