How do you convert a string "123456" to integer without using any library function? This is the question people applying for senior developers have failed to answer at my company.
Know basic OOP concepts..
difference between inheritance and abstract classes.
Pass by value and pass by reference.
Extended methods.
SQL - joins, pivot, indexing...
JSON, XML
ASP.NET Page Cycle,
random .net stuffs etc.etc.etc.
REST services. Learn how to use Rest API.
MVC -> beneficial to know. but at entry level i don't think anyone would expect you to know WCF , entity framework.
Linq is good to know.
Lambda expressions.(good to know.. or get Resharper license -> convert foreach to lambda !!! :D)
if you are going to interview where there are front end developers you don't need to know Jquery or Javascript; However it's good to know.

Post your keywords in resume and i can add more questions. If you have ADO.net in resume chances are you will get questions about ADO.NET. So make sure you familiarize with stuffs you have in your resume.

Good Luck