A clean shirt and shoes without dirt ?

To be honest, that's such a general question that it can't be answered. Check out your local newspaper or the companies websites for job offers.
That'll do the job ...

I work for a chip firm in Sunnyvale, CA, and in my department we hire about 10 new grads a year as Applications Engineers.  If you don't pass our screen for understanding of basic analog circuitry you don't get an interview.  The questions get a bit tougher when you come for interview.  The biggest issue we face is that new grads often don't have a good grounding in analog.  We speculate that classes on digital topics are of more interest to the majority of students.  So a student who has a real passion for analog will probably have gained a good understanding of the analog basics during his undergrad years, and he'll shine in our evaluations.

We also value work ethic, and an ability to talk to customers.  So you get extra credit if you worked as a waiter to pay your way through college -- seriously!  Of course, maturity is important to us as well.  We want people who will keep their commitments and will show up on time when they have meetings or specific duties.  And you have to dress for the interview -- no, I don't much care how you dress per se, but I do care that you have the maturity and foresight to know that dressing well is expected in interview situations.

Good luck!