I know that there are a lot of offers in London for LLM in this subjects, but I still don't know for sure which one is better. Can any of you give a ranking in this matter??? I'm totally lost and I don't wanna end up enrolling in some LLM that is not good at all.
Are this LondonMet's LLM any good: a) Financial Services Law; b) International Banking and Insurance Law; c) International Economic Law
Thanks for the help!

i believe you cannot run away from the established UCL KCL LSE within london. between these 3, it would be a matter of opinion and specialisation. but I would rate them
1) UCL
2) KCL
3) LSE
But this is not a definitive benchmark.

all other institutions will always be 2nd rate when compared.

In a ranking of English Universities, I read that the LondonMet was rated #73... and in the Law School Rankings of www.llm-guide.com it doesn't even appear. Is it really that bad?

unfortunately that institution is not highly regarded. but don;t get me wrong, if your objective is to further your understanding in the area, im sure it would be beneficial to you in any event.