What topics should one master if one wants to pursue a Master's degree in mathematics at a top university? This fall I am starting the 3rd year of my bachelor's degree and I intend to continue my studies with a Master's degree and possibly a PhD. The university I study at is a respected institution in my country but not particularly focused on my area of interest (algebra). I had a first contact, at a summer school, with students from top universities in Europe and I realised I am under prepared for a Master's at one of these universities. 

I have a good academic record and did some undergraduate research but there are topics I know nothing about. For example in algebra I had only 2 undergraduate courses (vector spaces, groups and rings- basic definition, properties, isomorphism theorems), no linear algebra aside from the matrix of a linear transformation.

So my question is: what courses are essential to someone who wants to go to graduate school in algebra at a good university and what should I study to bridge the gap?

Edit: I already took all the undergraduate and graduate level classes available in my field,at my university, but all those were still under the level of preparation of my peers from other universities. So I was asking for subjects I should know in order to study by myself.
The simple answer is that if you're interested in a subject and expect to continue on to a master's or PhD (or even if you're not expecting to go for an advanced degree, you simply expect to pursue it as a career), you should take as many classes in that subject as you can.  Pick the best or most interesting to you from whatever is offered by your department to fill out your electives and do your best.